初二上化简求值题100道!急急急急 初二上化简求值题100道!急急急急。
20\u9898\uff0c\u521d\u4e00\u6570\u5b66\uff0c\u5316\u7b80\u6c42\u503c\uff0c\u8c22\u8c22\uff0c\u6025\u6025\u60251\u3001\u5df2\u77e5A,B\u662f\u65b9\u7a0bx^2+2x-5=0\u7684\u4e24\u4e2a\u5b9e\u6570\u6839,
\u6c42(A^2+2AB+2A)(B^2+2AB+2B)\u7684\u503c.
\u7531A,B\u662f\u65b9\u7a0bx^2+2x-5=0\u7684\u4e24\u4e2a\u5b9e\u6570\u6839\u5f97\uff1a
AB=-5\uff0cA+B=-2
A^2+2AB+2A)(B^2+2AB+2B)
=AB\uff08A+2B+2\uff09\uff08B+2A+2\uff09
=-5\uff08-2+B+2\uff09\uff08-2+A+2\uff09
=-5AB
=25
2\u30011/2(x+y+z)\u65b9+1/2(x-y-z)(x-y+z)-z(x+y),\u5176\u4e2dx-y=6,xy=21.\u8981\u8be6\u7ec6\u6b65\u9aa4
\u5316\u7b80\u5f97\uff1a
1/2(x+y+z)\u65b9+1/2(x-y-z)(x-y+z)-z(x+y)=
1/2[(x+y)\u65b9+2z(x+y)+z\u65b9]+1/2[(x-y)\u65b9-z\u65b9]-z(x+y)=
1/2(x+y)\u65b9+1/2(x-y)\u65b9=x\u65b9\uff0by\u65b9
\u7531x-y=6,xy=21\u5f97\uff0cx\u65b9\uff0by\u65b9\uff1d\uff08x-y\uff09\u65b9\uff0b2xy\uff1d78
3\u3001a^2-ab+2b^2=3 \u6c422ab-2a^2-4b^2-7\u7684\u503c
2ab-2a^2-4b^2-7
=2(ab-a^2-2b^2)-7
=-2(a^2-ab+2b^2)-7
=(-2)*3-7
=-6-7=-13
4\u3001\u82e5A=2x^2+3xy-2x-3,B=-x^2+xy+2,\u4e143A+6B\u7684\u503c\u4e0ex\u65e0\u5173\uff0c\u6c42y\u7684\u503c
\u89e3\uff1a
3A+6B=6x^2+9xy-6x-9-6x^2+6xy+12
=15xy-6x+3
=x(15y-6)+3
5\u30019x+6x^2 -3(x-2/3x^2).\u5176\u4e2dx=-2
9x+6x² -3(x-2/3x²)
=9x+6x²-3x+2x²
=8x²+6x
=8\u00d7(-2)²+6\u00d7(-2)
=32-12
=20
6\u30011/4(-4x^2+2x-8)-(1/2x-1),\u5176\u4e2dx=1/2
1/4(-4x²+2x-8)-(1/2x-1)
=-x²+1/2x-2-1/2x+1
=-x²-1
=-(1/2)²-1
=-1/4-1
=-5/4
7\u30013x'y-[2x'y-(2xyz-x'z)-4x'z]-xyz,\u5176\u4e2dx=-2,y=-3,z=1,
:3x'y-[2x'y-(2xyz-x'z)-4x'z]-xyz
=3x'y-2x'y+2xyz-x'z+4x'z-xyz
=x'y-xyz+3x'z
=4*(-3)-2*3*1+3*4*1
=-12-6+12
=-6
8\u3001(5a^2-3b^2)+(a^2+b^2)-(5a^2+3b^2),\u5176\u4e2da=-1,b=1
=5a^2-3b^2+a^2+b^2-5a^2-3b^2
=a^2-5b^2
=(-1)^2-5*1^2
=1-5
=-4
9\u30012(a^2b+ab^2)-2(a^2 b-1)-2ab^2 -2\u5176\u4e2da=-2,b=2
=2a^2b+2ab^2-2a^2b+2-2ab^2-2
=0
10\u3001(X-2\u5206\u4e4b1Y-1)(X-2\u5206\u4e4b1Y+1)-(X-2\u5206\u4e4b1Y-1)\u7684\u5e73\u65b9
\u5176\u4e2dX=1.7,Y=3.9(\u5148\u5316\u7b80\u518d\u6c42\u503c)
[(X-2\u5206\u4e4b1Y)-1][(X+2\u5206\u4e4b1Y)+1]-(X-2\u5206\u4e4b1Y-1)\u5e73\u65b9
=(X+2\u5206\u4e4b1Y)\u5e73\u65b9-1-(X-2\u5206\u4e4b1Y)\u5e73\u65b9+2(X-2\u5206\u4e4b1Y)-1
=(X+2\u5206\u4e4b1Y)\u5e73\u65b9-(X-2\u5206\u4e4b1Y)\u5e73\u65b9+2(X-2\u5206\u4e4b1Y)-2
=2XY+2X-Y-2
=3.9*2.4+1.4
=10.76
\u5316\u95f4\u6c42\u503c: \u4e0b\u9762\u7684\u4f60\u81ea\u5df1\u6c42\u5427```
1\u3001-9(x-2)-y(x-5)
\uff081\uff09\u5316\u7b80\u6574\u4e2a\u5f0f\u5b50\u3002
\uff082\uff09\u5f53x=5\u65f6\uff0c\u6c42y\u7684\u89e3\u3002
2\u30015(9+a)\u00d7b-5(5+b)\u00d7a
\uff081\uff09\u5316\u7b80\u6574\u4e2a\u5f0f\u5b50\u3002
\uff082\uff09\u5f53a=5/7\u65f6\uff0c\u6c42\u5f0f\u5b50\u7684\u503c\u3002
3\u300162g+62(g+b)-b
\uff081\uff09\u5316\u7b80\u6574\u4e2a\u5f0f\u5b50\u3002
\uff082\uff09\u5f53g=5/7\u65f6\uff0c\u6c42b\u7684\u89e3\u3002
4\u30013(x+y)-5(4+x)+2y
\uff081\uff09\u5316\u7b80\u6574\u4e2a\u5f0f\u5b50\u3002
5\u3001(x+y)(x-y)
\uff081\uff09\u5316\u7b80\u6574\u4e2a\u5f0f\u5b50\u3002
6\u30012ab+a\u00d7a-b
\uff081\uff09\u5316\u7b80\u6574\u4e2a\u5f0f\u5b50\u3002
7\u30015.6x+4(x+y)-y
\uff081\uff09\u5316\u7b80\u6574\u4e2a\u5f0f\u5b50\u3002
8\u30016.4(x+2.9)-y+2(x-y)
\uff081\uff09\u5316\u7b80\u6574\u4e2a\u5f0f\u5b50\u3002
9\u3001(2.5+x)(5.2+y)
\uff081\uff09\u5316\u7b80\u6574\u4e2a\u5f0f\u5b50\u3002
10\u30019.77x-(5-a)x+2a
(5a^2-3b^2)+(a^2+b^2)-(5a^2+3b^2),\u5176\u4e2da=-1,b=1
=5a^2-3b^2+a^2+b^2-5a^2-3b^2
=a^2-5b^2
=(-1)^2-5*1^2
=1-5
=-4
2(a^2b+ab^2)-2(a^2 b-1)-2ab^2 -2\u5176\u4e2da=-2,b=2
=2a^2b+2ab^2-2a^2b+2-2ab^2-2
=0
x+7-(-36+8^2)/2=[-(-8x)+7^4]/3*(8^2-6x)
(a-7)-(-98a)+7a=[(3.2*5a)2^5]/10
(89/2+5x)+35/6x=[3*(-9+5)+2^3]/5+7x
[3X+(-189+5^2)/3]/8=521/2
4y+[119*(-5^3y+8/7)-8/3]=22/11
(3X*189)+{5*6+[-5/8*(-65*8^3)]+9/2}
7(2x-1)-3(4x-1)=4(3x+2)-1
(5y+1)+ (1-y)= (9y+1)+ (1-3y)
[-6(-7^4*8)-4]=x+2
20%+(1-20%)(320-x)=320\u00d740%
2(x-2)+2=x+1
2(x-2)-3(4x-1)=9(1-x)
11x+64-2x=100-9x
15-(8-5x)=7x+(4-3x)
3(x-7)-2[9-4(2-x)]=22
3/2[2/3(1/4x-1)-2]-x=2
2x+7^2=157
9x+6x² -3(x-2/3x²)
=9x+6x²-3x+2x²
=8x²+6x
=8\u00d7(-2)²+6\u00d7(-2)
=32-12
=20
1/4(-4x²+2x-8)-(1/2x-1)
=-x²+1/2x-2-1/2x+1
=-x²-1
=-(1/2)²-1
=-1/4-1
=-5/4
3\uff0e3ab-4ab+8ab-7ab+ab=______\uff0e
4\uff0e7x-(5x-5y)-y=______\uff0e
5\uff0e23a3bc2-15ab2c+8abc-24a3bc2-8abc=______\uff0e
6\uff0e-7x2+6x+13x2-4x-5x2=______\uff0e
7\uff0e2y+(-2y+5)-(3y+2)\uff1d______\uff0e
11\uff0e(2x2-3xy+4y2)+(x2+2xy-3y2)=______\uff0e
12\uff0e2a-(3a-2b+2)+(3a-4b-1)=______\uff0e
13\uff0e-6x2-7x2+15x2-2x2\uff1d______\uff0e
14\uff0e2x-(x+3y)-(-x-y)-(x-y)\uff1d______\uff0e
16\uff0e2x+2y-[3x-2(x-y)]=______\uff0e
17\uff0e5-(1-x)-1-(x-1)=______\uff0e
18\uff0e( )+(4xy+7x2-y2)=10x2-xy\uff0e
19\uff0e(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3\uff0e
21\uff0e\u5df2\u77e5A=x3-2x2+x-4\uff0cB=2x3-5x+3\uff0c\u8ba1\u7b97A+B=______\uff0e
22\uff0e\u5df2\u77e5A=x3-2x2+x-4\uff0cB=2x3-5x+3\uff0c\u8ba1\u7b97A-B=______\uff0e
23\uff0e\u82e5a=-0.2\uff0cb=0.5\uff0c\u4ee3\u6570\u5f0f-(|a2b|-|ab2|)\u7684\u503c\u4e3a______\uff0e
25\uff0e\u4e00\u4e2a\u591a\u9879\u5f0f\u51cf\u53bb3m4-m3-2m+5\u5f97-2m4-3m3-2m2-1\uff0c\u90a3\u4e48\u8fd9\u4e2a\u591a\u9879\u5f0f\u7b49\u4e8e______\uff0e
26\uff0e-(2x2-y2)-[2y2-(x2+2xy)]=______\uff0e
27\uff0e\u82e5-3a3b2\u4e0e5ax-1by+2\u662f\u540c\u7c7b\u9879\uff0c\u5219x=______\uff0cy=______\uff0e
28\uff0e(-y+6+3y4-y3)-(2y2-3y3+y4-7)\uff1d______\uff0e
29\uff0e\u5316\u7b80\u4ee3\u6570\u5f0f4x2-[7x2-5x-3(1-2x+x2)]\u7684\u7ed3\u679c\u662f______\uff0e
30\uff0e2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( )\uff0e
31\uff0e3a-(2a-3b)+3(a-2b)-b=______\uff0e
32\uff0e\u5316\u7b80\u4ee3\u6570\u5f0fx-[y-2x-(x+y)]\u7b49\u4e8e______\uff0e
33\uff0e[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1\uff0e
34\uff0e3x-[y-(2x+y)]=______\uff0e
35\uff0e\u5316\u7b80|1-x+y|-|x-y|(\u5176\u4e2dx\uff1c0\uff0cy\uff1e0)\u7b49\u4e8e______\uff0e
36\uff0e\u5df2\u77e5x\u2264y\uff0cx+y-|x-y|=______\uff0e
37\uff0e\u5df2\u77e5x\uff1c0\uff0cy\uff1c0\uff0c\u5316\u7b80|x+y|-|5-x-y|=______\uff0e
38\uff0e4a2n-an-(3an-2a2n)\uff1d______\uff0e
39\uff0e\u82e5\u4e00\u4e2a\u591a\u9879\u5f0f\u52a0\u4e0a-3x2y+2x2-3xy-4\u5f97
2x2y+3xy2-x2+2xy\uff0c
\u5219\u8fd9\u4e2a\u591a\u9879\u5f0f\u4e3a______\uff0e
40\uff0e-5xm-xm-(-7xm)+(-3xm)=______\uff0e
41\uff0e\u5f53a=-1\uff0cb=-2\u65f6\uff0c
[a-(b-c)]-[-b-(-c-a)]\uff1d______\uff0e
43\uff0e\u5f53a=-1\uff0cb=1\uff0cc=-1\u65f6\uff0c
-[b-2(-5a)]-(-3b+5c)\uff1d______\uff0e
44\uff0e-2(3x+z)-(-6x)+(-5y+3z)=______\uff0e
45\uff0e-5an-an+1-(-7an+1)+(-3an)\uff1d______\uff0e
46\uff0e3a-(2a-4b-6c)+3(-2c+2b)=______\uff0e
48\uff0e9a2+[7a2-2a-(-a2+3a)]=______\uff0e
50\uff0e\u5f532y-x=5\u65f6\uff0c5(x-2y)2-3(-x+2y)-100=______\uff0e
(\u4e8c)\u9009\u62e9
[ ]
A\uff0e2\uff1b
B\uff0e-2\uff1b
C\uff0e-10\uff1b
D\uff0e-6\uff0e
52\uff0e\u4e0b\u5217\u5404\u5f0f\u4e2d\u8ba1\u7b97\u7ed3\u679c\u4e3a-7x-5x2+6x3\u7684\u662f [ ]
A\uff0e3x-(5x2+6x3-10x)\uff1b
B\uff0e3x-(5x2+6x3+10x)\uff1b
C\uff0e3x-(5x2-6x3+10x)\uff1b
D\uff0e3x-(5x2-6x3-10x)\uff0e
53\uff0e\u628a(-x-y)+3(x+y)-5(x+y)\u5408\u5e76\u540c\u7c7b\u9879\u5f97 [ ]
A\uff0e(x-y)-2(x+y)\uff1b
B\uff0e-3(x+y)\uff1b
C\uff0e(-x-y)-2(x+y)\uff1b
D\uff0e3(x+y)\uff0e
54\uff0e2a-[3b-5a-(2a-7b)]\u7b49\u4e8e [ ]
A\uff0e-7a+10b\uff1b
B\uff0e5a+4b\uff1b
C\uff0e-a-4b\uff1b
D\uff0e9a-10b\uff0e
55\uff0e\u51cf\u53bb-3m\u7b49\u4e8e5m2-3m-5\u7684\u4ee3\u6570\u5f0f\u662f [ ]
A\uff0e5(m2-1)\uff1b
B\uff0e5m2-6m-5\uff1b
C\uff0e5(m2+1)\uff1b
D\uff0e-(5m2+6m-5)\uff0e
56\uff0e\u5c06\u591a\u9879\u5f0f2ab-9a2-5ab-4a2\u4e2d\u7684\u540c\u7c7b\u9879\u5206\u522b\u7ed3\u5408\u5728\u4e00\u8d77\uff0c\u5e94\u4e3a [ ]
A\uff0e(9a2-4a2)+(-2ab-5ab)\uff1b
B\uff0e(9a2+4a2)-(2ab-5ab)\uff1b
C\uff0e(9a2-4a2)-(2ab+5ab)\uff1b
D\uff0e(9a2-4a2)+(2ab-5ab)\uff0e
57\uff0e\u5f53a=2\uff0cb=1\u65f6\uff0c-a2b+3ba2-(-2a2b)\u7b49\u4e8e [ ]
A\uff0e20\uff1b
B\uff0e24\uff1b
C\uff0e0\uff1b
D\uff0e16\uff0e
\u4e2d\uff0c\u6b63\u786e\u7684\u9009\u62e9\u662f [ ]
A\uff0e\u6ca1\u6709\u540c\u7c7b\u9879\uff1b
B\uff0e(2)\u4e0e(4)\u662f\u540c\u7c7b\u9879\uff1b
C\uff0e(2)\u4e0e(5)\u662f\u540c\u7c7b\u9879\uff1b
D\uff0e(2)\u4e0e(4)\u4e0d\u662f\u540c\u7c7b\u9879\uff0e
59\uff0e\u82e5A\u548cB\u5747\u4e3a\u4e94\u6b21\u591a\u9879\u5f0f\uff0c\u5219A-B\u4e00\u5b9a\u662f [ ]
A\uff0e\u5341\u6b21\u591a\u9879\u5f0f\uff1b
B\uff0e\u96f6\u6b21\u591a\u9879\u5f0f\uff1b
C\uff0e\u6b21\u6570\u4e0d\u9ad8\u4e8e\u4e94\u6b21\u7684\u591a\u9879\u5f0f\uff1b
D\uff0e\u6b21\u6570\u4f4e\u4e8e\u4e94\u6b21\u7684\u591a\u9879\u5f0f\uff0e
60\uff0e-\uff5b[-(x+y)]\uff5d+\uff5b-[(x+y)]\uff5d\u7b49\u4e8e [ ]
A\uff0e0\uff1b
B\uff0e-2y\uff1b
C\uff0ex+y\uff1b
D\uff0e-2x-2y\uff0e
61\uff0e\u82e5A=3x2-5x+2\uff0cB=3x2-5x+6\uff0c\u5219A\u4e0eB\u7684\u5927\u5c0f\u662f
[ ]
A\uff0eA\uff1eB\uff1b
B\uff0eA=B\uff1b
C\uff0eA\uff1cB\uff1b
D\uff0e\u65e0\u6cd5\u786e\u5b9a\uff0e
62\uff0e\u5f53m=-1\u65f6\uff0c-2m2-[-4m2+(-m2)]\u7b49\u4e8e [ ]
A\uff0e-7\uff1b
B\uff0e3\uff1b
C\uff0e1\uff1b
D\uff0e2\uff0e
63\uff0e\u5f53m=2\uff0cn=1\u65f6\uff0c\u591a\u9879\u5f0f-m-[-(2m-3n)]+[-(-3m)-4n]\u7b49\u4e8e [ ]
A\uff0e1\uff1b
B\uff0e9\uff1b
C\uff0e3\uff1b
D\uff0e5\uff0e
[ ]
65\uff0e-5an-an-(-7an)+(-3an)\u7b49\u4e8e [ ]
A\uff0e-16an\uff1b
B\uff0e-16\uff1b
C\uff0e-2an\uff1b
D\uff0e-2\uff0e
66\uff0e(5a-3b)-3(a2-2b)\u7b49\u4e8e [ ]
A\uff0e3a2+5a+3b\uff1b
B\uff0e2a2+3b\uff1b
C\uff0e2a3-b2\uff1b
D\uff0e-3a2+5a-5b\uff0e
67\uff0ex3-5x2-4x+9\u7b49\u4e8e [ ]
A\uff0e(x3-5x2)-(-4x+9)\uff1b
B\uff0ex3-5x2-(4x+9)\uff1b
C\uff0e-(-x3+5x2)-(4x-9)\uff1b
D\uff0ex3+9-(5x2-4x)\uff0e
[ ]
69\uff0e4x2y-5xy2\u7684\u7ed3\u679c\u5e94\u4e3a [ ]
A\uff0e-x2y\uff1b
B\uff0e-1\uff1b
C\uff0e-x2y2\uff1b
D\uff0e\u4ee5\u4e0a\u7b54\u6848\u90fd\u4e0d\u5bf9\uff0e
(\u4e09)\u5316\u7b80
70\uff0e(4x2-8x+5)-(x3+3x2-6x+2)\uff0e
72\uff0e(0.3x3-x2y+xy2-y3)-(-0.5x3-x2y+0.3xy2)\uff0e
73\uff0e-{2a2b-[3abc-(4ab2-a2b)]\uff5d\uff0e
74\uff0e(5a2b+3a2b2-ab2)-(-2ab2+3a2b2+a2b)\uff0e
75\uff0e(x2-2y2-z2)-(-y2+3x2-z2)+(5x2-y2+2z2)\uff0e
76\uff0e(3a6-a4+2a5-4a3-1)-(2-a+a3-a5-a4)\uff0e
77\uff0e(4a-2b-c)-5a-[8b-2c-(a+b)]\uff0e
78\uff0e(2m-3n)-(3m-2n)+(5n+m)\uff0e
79\uff0e(3a2-4ab-5b2)-(2b2-5a2+2ab)-(-6ab)\uff0e
80\uff0exy-(2xy-3z)+(3xy-4z)\uff0e
81\uff0e(-3x3+2x2-5x+1)-(5-6x-x2+x3)\uff0e
83\uff0e3x-(2x-4y-6x)+3(-2z+2y)\uff0e
84\uff0e(-x2+4+3x4-x3)-(x2+2x-x4-5)\uff0e
85\uff0e\u82e5A=5a2-2ab+3b2\uff0cB=-2b2+3ab-a2\uff0c\u8ba1\u7b97A+B\uff0e
86\uff0e\u5df2\u77e5A=3a2-5a-12\uff0cB=2a2+3a-4\uff0c\u6c422(A-B)\uff0e
87\uff0e2m-{-3n+[-4m-(3m-n)]\uff5d\uff0e
88\uff0e5m2n+(-2m2n)+2mn2-(+m2n)\uff0e
89\uff0e4(x-y+z)-2(x+y-z)-3(-x-y-z)\uff0e
90\uff0e2(x2-2xy+y2-3)+(-x2+y2)-(x2+2xy+y2)\uff0e
92\uff0e2(a2-ab-b2)-3(4a-2b)+2(7a2-4ab+b2)\uff0e
94\uff0e4x-2(x-3)-3[x-3(4-2x)+8]\uff0e
(\u56db)\u5c06\u4e0b\u5217\u5404\u5f0f\u5148\u5316\u7b80\uff0c\u518d\u6c42\u503c
97\uff0e\u5df2\u77e5a+b=2\uff0ca-b=-1\uff0c\u6c423(a+b)2(a-b)2-5(a+b)2\u00d7(a-b)2\u7684\u503c\uff0e
98\uff0e\u5df2\u77e5A=a2+2b2-3c2\uff0cB=-b2-2c2+3a2\uff0cC=c2+2a2-3b2\uff0c\u6c42(A-B)+C\uff0e
99\uff0e\u6c42(3x2y-2xy2)-(xy2-2x2y)\uff0c\u5176\u4e2dx=-1\uff0cy=2\uff0e
101\uff0e\u5df2\u77e5|x+1|+(y-2)2=0\uff0c\u6c42\u4ee3\u6570\u5f0f5(2x-y)-3(x-4y)\u7684\u503c\uff0e
106\uff0e\u5f53P=a2+2ab+b2\uff0cQ=a2-2ab-b2\u65f6\uff0c\u6c42P-[Q-2P-(P-Q)]\uff0e
107\uff0e\u6c422x2-\uff5b-3x+5+[4x2-(3x2-x-1)]\uff5d\u7684\u503c\uff0c\u5176\u4e2dx=-3\uff0e
110\uff0e\u5f53x=-2\uff0cy=-1\uff0cz=3\u65f6\uff0c\u6c425xyz-\uff5b2x2y-[3xyz-(4xy2-x2y)]\uff5d\u7684\u503c\uff0e
113\uff0e\u5df2\u77e5A=x3-5x2\uff0cB=x2-6x+3\uff0c\u6c42A-3(-2B)\uff0e
(\u4e94)\u7efc\u5408\u7ec3\u4e60
115\uff0e\u53bb\u62ec\u53f7\uff1a\uff5b-[-(a+b)]\uff5d-\uff5b-[-(a-b)]\uff5d\uff0e
116\uff0e\u53bb\u62ec\u53f7\uff1a-[-(-x)-y]-[+(-y)-(+x)]\uff0e
117\uff0e\u5df2\u77e5A=x3+6x-9\uff0cB=-x3-2x2+4x-6\uff0c\u8ba1\u7b972A-3B\uff0c\u5e76\u628a\u7ed3\u679c\u653e\u5728\u524d\u9762\u5e26\u201c-\u201d\u53f7\u7684\u62ec\u53f7\u5185\uff0e
118\uff0e\u8ba1\u7b97\u4e0b\u5f0f\uff0c\u5e76\u628a\u7ed3\u679c\u653e\u5728\u524d\u9762\u5e26\u201c-\u201d\u53f7\u7684\u62ec\u53f7\u5185\uff1a
(-7y2)+(-4y)-(-y2)-(+5y)+(-8y2)+(+3y)\uff0e
119\uff0e\u53bb\u62ec\u53f7\u3001\u5408\u5e76\u540c\u7c7b\u9879\uff0c\u5c06\u7ed3\u679c\u6309x\u7684\u5347\u5e42\u6392\u5217\uff0c\u5e76\u628a\u540e\u4e09\u9879\u653e\u5728\u5e26\u6709\u201c-\u201d\u53f7\u7684\u62ec\u53f7\u5185\uff1a
120\uff0e\u4e0d\u6539\u53d8\u4e0b\u5f0f\u7684\u503c\uff0c\u5c06\u5176\u4e2d\u5404\u62ec\u53f7\u524d\u7684\u7b26\u53f7\u90fd\u53d8\u6210\u76f8\u53cd\u7684\u7b26\u53f7\uff1a(x3+3x2)-(3x2y-7xy)+(2y3-3y2)\uff0e
121\uff0e\u628a\u591a\u9879\u5f0f4x2y-2xy2+4xy+6-x2y2+x3-y2\u7684\u4e09\u6b21\u9879\u653e\u5728\u524d\u9762\u5e26\u6709\u201c-\u201d\u53f7\u7684\u62ec\u53f7\u5185\uff0c\u4e8c\u6b21\u9879\u653e\u5728\u524d\u9762\u5e26\u6709\u201c+\u201d\u53f7\u7684\u62ec\u53f7\u5185\uff0c\u56db\u6b21\u9879\u548c\u5e38\u6570\u9879\u653e\u5728\u524d\u9762\u5e26\u6709\u201c-\u201d\u53f7\u7684\u62ec\u53f7\u5185\uff0e
122\uff0e\u628a\u4e0b\u5217\u591a\u9879\u5f0f\u7684\u62ec\u53f7\u53bb\u6389\uff0c\u5408\u5e76\u540c\u7c7b\u9879\uff0c\u5e76\u5c06\u5176\u5404\u9879\u653e\u5728\u524d\u9762\u5e26\u6709\u201c-\u201d\u53f7\u7684\u62ec\u53f7\u5185\uff0c\u518d\u6c422x-2[3x-(5x2-2x+1)]-4x2\u7684\u503c\uff0c\u5176\u4e2dx=-1\uff0e
123\uff0e\u5408\u5e76\u540c\u7c7b\u9879\uff1a
7x-1.3z-4.7-3.2x-y+2.1z+5-0.1y\uff0e
124\uff0e\u5408\u5e76\u540c\u7c7b\u9879\uff1a5m2n+5mn2-mn+3m2n-6mn2-8mn\uff0e
126\uff0e\u53bb\u62ec\u53f7\uff0c\u5408\u5e76\u540c\u7c7b\u9879\uff1a
(1)(m+1)-(-n+m)\uff1b
(2)4m-[5m-(2m-1)]\uff0e
127\uff0e\u5316\u7b80\uff1a2x2-\uff5b-3x-[4x2-(3x2-x)+(x-x2)]\uff5d\uff0e
128\uff0e\u5316\u7b80\uff1a-(7x-y-2z)-\uff5b[4x-(x-y-z)-3x+z]-x\uff5d\uff0e
129\uff0e\u8ba1\u7b97\uff1a(+3a)+(-5a)+(-7a)+(-31a)-(+4a)-(-8a)\uff0e
130\uff0e\u5316\u7b80\uff1aa3-(a2-a)+(a2-a+1)-(1-a4+a3)\uff0e
131\uff0e\u5c06x2-8x+2x3-13x2-2x-2x3+3\u5148\u5408\u5e76\u540c\u7c7b\u9879\uff0c\u518d\u6c42\u503c\uff0c\u5176\u4e2dx=-4\uff0e
132\uff0e\u5728\u62ec\u53f7\u5185\u586b\u4e0a\u9002\u5f53\u7684\u9879\uff1a[( )-9y+( )]+2y2+3y-4=11y2-( )+13\uff0e
133\uff0e\u5728\u62ec\u53f7\u5185\u586b\u4e0a\u9002\u5f53\u7684\u9879\uff1a
(-x+y+z)(x+y-z)=[y-( )][y+( )]\uff0e
134\uff0e\u5728\u62ec\u53f7\u5185\u586b\u4e0a\u9002\u5f53\u7684\u9879\uff1a
(3x2+xy-7y2)-( )=y2-2xy-x2\uff0e
135\uff0e\u5728\u62ec\u53f7\u5185\u586b\u4e0a\u9002\u5f53\u7684\u9879\uff1a
(1)x2-xy+y-1=x2-( )\uff1b
(2)[( )+6x-7]-[4x2+( )-( )]=x2-2x+1\uff0e
136\uff0e\u8ba1\u7b974x2-3[x+4(1-x)-x2]-2(4x2-1)\u7684\u503c\uff0e
137\uff0e\u5316\u7b80\uff1a
138\uff0e\u7528\u7ad6\u5f0f\u8ba1\u7b97
(-x+5+2x4-6x3)-(3x4+2x2-3x3-7)\uff0e
139\uff0e\u5df2\u77e5A=11x3+8x2-6x+2\uff0cB=7x3-x2+x+3\uff0c\u6c422(3A-2B)\uff0e
140\uff0e\u5df2\u77e5A=x3-5x2\uff0cB=x3-11x+6\uff0cC=4x-3\uff0c\u6c42
(1)A-B-C\uff1b
(2)(A-B-C)-(A-B+C)\uff0e
141\uff0e\u5df2\u77e5A=3x2-4x3\uff0cB=x3-5x2+2\uff0c\u8ba1\u7b97
(1)A+B\uff1b
(2)B-A\uff0e
142\uff0e\u5df2\u77e5x\uff1c-4\uff0c\u5316\u7b80|-x|+|x+4|-|x-4|\uff0e
146\uff0e\u6c42\u4e24\u4ee3\u6570\u5f0f-1.56a+3.2a3-0.47\uff0c2.27a3-0.02a2+4.03a+0.53\u7684\u5dee\u4e0e6-0.15a+3.24a2+5.07a3\u7684\u548c\uff0e
-0.3\uff0cy=-0.2\uff0e
150\uff0e\u5df2\u77e5(x-3)2+|y+1|+z2=0\uff0c\u6c42x2-2xy-5x2+12xz+3xy-z2-8xz-2x2\u7684\u503c\uff0e
求(A^2+2AB+2A)(B^2+2AB+2B)的值.
由A,B是方程x^2+2x-5=0的两个实数根得:
AB=-5,A+B=-2
A^2+2AB+2A)(B^2+2AB+2B)
=AB(A+2B+2)(B+2A+2)
=-5(-2+B+2)(-2+A+2)
=-5AB
=25
2、1/2(x+y+z)方+1/2(x-y-z)(x-y+z)-z(x+y),其中x-y=6,xy=21.要详细步骤
化简得:
1/2(x+y+z)方+1/2(x-y-z)(x-y+z)-z(x+y)=
1/2[(x+y)方+2z(x+y)+z方]+1/2[(x-y)方-z方]-z(x+y)=
1/2(x+y)方+1/2(x-y)方=x方+y方
由x-y=6,xy=21得,x方+y方=(x-y)方+2xy=78
3、a^2-ab+2b^2=3 求2ab-2a^2-4b^2-7的值
2ab-2a^2-4b^2-7
=2(ab-a^2-2b^2)-7
=-2(a^2-ab+2b^2)-7
=(-2)*3-7
=-6-7=-13
4、若A=2x^2+3xy-2x-3,B=-x^2+xy+2,且3A+6B的值与x无关,求y的值
解:
3A+6B=6x^2+9xy-6x-9-6x^2+6xy+12
=15xy-6x+3
=x(15y-6)+3
5、9x+6x^2 -3(x-2/3x^2).其中x=-2
9x+6x�0�5 -3(x-2/3x�0�5)
=9x+6x�0�5-3x+2x�0�5
=8x�0�5+6x
=8×(-2)�0�5+6×(-2)
=32-12
=20
6、1/4(-4x^2+2x-8)-(1/2x-1),其中x=1/2
1/4(-4x�0�5+2x-8)-(1/2x-1)
=-x�0�5+1/2x-2-1/2x+1
=-x�0�5-1
=-(1/2)�0�5-1
=-1/4-1
=-5/4
7、3x'y-[2x'y-(2xyz-x'z)-4x'z]-xyz,其中x=-2,y=-3,z=1,
:3x'y-[2x'y-(2xyz-x'z)-4x'z]-xyz
=3x'y-2x'y+2xyz-x'z+4x'z-xyz
=x'y-xyz+3x'z
=4*(-3)-2*3*1+3*4*1
=-12-6+12
=-6
8、(5a^2-3b^2)+(a^2+b^2)-(5a^2+3b^2),其中a=-1,b=1
=5a^2-3b^2+a^2+b^2-5a^2-3b^2
=a^2-5b^2
=(-1)^2-5*1^2
=1-5
=-4
9、2(a^2b+ab^2)-2(a^2 b-1)-2ab^2 -2其中a=-2,b=2
=2a^2b+2ab^2-2a^2b+2-2ab^2-2
=0
10、(X-2分之1Y-1)(X-2分之1Y+1)-(X-2分之1Y-1)的平方
其中X=1.7,Y=3.9(先化简再求值)
[(X-2分之1Y)-1][(X+2分之1Y)+1]-(X-2分之1Y-1)平方
=(X+2分之1Y)平方-1-(X-2分之1Y)平方+2(X-2分之1Y)-1
=(X+2分之1Y)平方-(X-2分之1Y)平方+2(X-2分之1Y)-2
=2XY+2X-Y-2
=3.9*2.4+1.4
=10.76
化间求值: 下面的你自己求吧```
1、-9(x-2)-y(x-5)
(1)化简整个式子。
(2)当x=5时,求y的解。
2、5(9+a)×b-5(5+b)×a
(1)化简整个式子。
(2)当a=5/7时,求式子的值。
3、62g+62(g+b)-b
(1)化简整个式子。
(2)当g=5/7时,求b的解。
4、3(x+y)-5(4+x)+2y
(1)化简整个式子。
5、(x+y)(x-y)
(1)化简整个式子。
6、2ab+a×a-b
(1)化简整个式子。
7、5.6x+4(x+y)-y
(1)化简整个式子。
8、6.4(x+2.9)-y+2(x-y)
(1)化简整个式子。
9、(2.5+x)(5.2+y)
(1)化简整个式子。
10、9.77x-(5-a)x+2a
(5a^2-3b^2)+(a^2+b^2)-(5a^2+3b^2),其中a=-1,b=1
=5a^2-3b^2+a^2+b^2-5a^2-3b^2
=a^2-5b^2
=(-1)^2-5*1^2
=1-5
=-4
2(a^2b+ab^2)-2(a^2 b-1)-2ab^2 -2其中a=-2,b=2
=2a^2b+2ab^2-2a^2b+2-2ab^2-2
=0
x+7-(-36+8^2)/2=[-(-8x)+7^4]/3*(8^2-6x)
(a-7)-(-98a)+7a=[(3.2*5a)2^5]/10
(89/2+5x)+35/6x=[3*(-9+5)+2^3]/5+7x
[3X+(-189+5^2)/3]/8=521/2
4y+[119*(-5^3y+8/7)-8/3]=22/11
(3X*189)+{5*6+[-5/8*(-65*8^3)]+9/2}
7(2x-1)-3(4x-1)=4(3x+2)-1
(5y+1)+ (1-y)= (9y+1)+ (1-3y)
[-6(-7^4*8)-4]=x+2
20%+(1-20%)(320-x)=320×40%
2(x-2)+2=x+1
2(x-2)-3(4x-1)=9(1-x)
11x+64-2x=100-9x
15-(8-5x)=7x+(4-3x)
3(x-7)-2[9-4(2-x)]=22
3/2[2/3(1/4x-1)-2]-x=2
2x+7^2=157
9x+6x�0�5 -3(x-2/3x�0�5)
=9x+6x�0�5-3x+2x�0�5
=8x�0�5+6x
=8×(-2)�0�5+6×(-2)
=32-12
=20
1/4(-4x�0�5+2x-8)-(1/2x-1)
=-x�0�5+1/2x-2-1/2x+1
=-x�0�5-1
=-(1/2)�0�5-1
=-1/4-1
=-5/4
3.3ab-4ab+8ab-7ab+ab=______.
4.7x-(5x-5y)-y=______.
5.23a3bc2-15ab2c+8abc-24a3bc2-8abc=______.
6.-7x2+6x+13x2-4x-5x2=______.
7.2y+(-2y+5)-(3y+2)=______.
11.(2x2-3xy+4y2)+(x2+2xy-3y2)=______.
12.2a-(3a-2b+2)+(3a-4b-1)=______.
13.-6x2-7x2+15x2-2x2=______.
14.2x-(x+3y)-(-x-y)-(x-y)=______.
16.2x+2y-[3x-2(x-y)]=______.
17.5-(1-x)-1-(x-1)=______.
18.( )+(4xy+7x2-y2)=10x2-xy.
19.(4xy2-2x2y)-( )=x3-2x2y+4xy2+y3.
21.已知A=x3-2x2+x-4,B=2x3-5x+3,计算A+B=______.
22.已知A=x3-2x2+x-4,B=2x3-5x+3,计算A-B=______.
23.若a=-0.2,b=0.5,代数式-(|a2b|-|ab2|)的值为______.
25.一个多项式减去3m4-m3-2m+5得-2m4-3m3-2m2-1,那么这个多项式等于______.
26.-(2x2-y2)-[2y2-(x2+2xy)]=______.
27.若-3a3b2与5ax-1by+2是同类项,则x=______,y=______.
28.(-y+6+3y4-y3)-(2y2-3y3+y4-7)=______.
29.化简代数式4x2-[7x2-5x-3(1-2x+x2)]的结果是______.
30.2a-b2+c-d3=2a+( )-d3=2a-d3-( )=c-( ).
31.3a-(2a-3b)+3(a-2b)-b=______.
32.化简代数式x-[y-2x-(x+y)]等于______.
33.[5a2+( )a-7]+[( )a2-4a+( )]=a2+2a+1.
34.3x-[y-(2x+y)]=______.
35.化简|1-x+y|-|x-y|(其中x<0,y>0)等于______.
36.已知x≤y,x+y-|x-y|=______.
37.已知x<0,y<0,化简|x+y|-|5-x-y|=______.
38.4a2n-an-(3an-2a2n)=______.
39.若一个多项式加上-3x2y+2x2-3xy-4得
2x2y+3xy2-x2+2xy,
则这个多项式为______.
40.-5xm-xm-(-7xm)+(-3xm)=______.
41.当a=-1,b=-2时,
[a-(b-c)]-[-b-(-c-a)]=______.
43.当a=-1,b=1,c=-1时,
-[b-2(-5a)]-(-3b+5c)=______.
44.-2(3x+z)-(-6x)+(-5y+3z)=______.
45.-5an-an+1-(-7an+1)+(-3an)=______.
46.3a-(2a-4b-6c)+3(-2c+2b)=______.
48.9a2+[7a2-2a-(-a2+3a)]=______.
50.当2y-x=5时,5(x-2y)2-3(-x+2y)-100=______.
(二)选择
[ ]
A.2;
B.-2;
C.-10;
D.-6.
52.下列各式中计算结果为-7x-5x2+6x3的是 [ ]
A.3x-(5x2+6x3-10x);
B.3x-(5x2+6x3+10x);
C.3x-(5x2-6x3+10x);
D.3x-(5x2-6x3-10x).
53.把(-x-y)+3(x+y)-5(x+y)合并同类项得 [ ]
A.(x-y)-2(x+y);
B.-3(x+y);
C.(-x-y)-2(x+y);
D.3(x+y).
54.2a-[3b-5a-(2a-7b)]等于 [ ]
A.-7a+10b;
B.5a+4b;
C.-a-4b;
D.9a-10b.
55.减去-3m等于5m2-3m-5的代数式是 [ ]
A.5(m2-1);
B.5m2-6m-5;
C.5(m2+1);
D.-(5m2+6m-5).
56.将多项式2ab-9a2-5ab-4a2中的同类项分别结合在一起,应为 [ ]
A.(9a2-4a2)+(-2ab-5ab);
B.(9a2+4a2)-(2ab-5ab);
C.(9a2-4a2)-(2ab+5ab);
D.(9a2-4a2)+(2ab-5ab).
57.当a=2,b=1时,-a2b+3ba2-(-2a2b)等于 [ ]
A.20;
B.24;
C.0;
D.16.
中,正确的选择是 [ ]
A.没有同类项;
B.(2)与(4)是同类项;
C.(2)与(5)是同类项;
D.(2)与(4)不是同类项.
59.若A和B均为五次多项式,则A-B一定是 [ ]
A.十次多项式;
B.零次多项式;
C.次数不高于五次的多项式;
D.次数低于五次的多项式.
60.-{[-(x+y)]}+{-[(x+y)]}等于 [ ]
A.0;
B.-2y;
C.x+y;
D.-2x-2y.
61.若A=3x2-5x+2,B=3x2-5x+6,则A与B的大小是
[ ]
A.A>B;
B.A=B;
C.A<B;
D.无法确定.
62.当m=-1时,-2m2-[-4m2+(-m2)]等于 [ ]
A.-7;
B.3;
C.1;
D.2.
63.当m=2,n=1时,多项式-m-[-(2m-3n)]+[-(-3m)-4n]等于 [ ]
A.1;
B.9;
C.3;
D.5.
[ ]
65.-5an-an-(-7an)+(-3an)等于 [ ]
A.-16an;
B.-16;
C.-2an;
D.-2.
66.(5a-3b)-3(a2-2b)等于 [ ]
A.3a2+5a+3b;
B.2a2+3b;
C.2a3-b2;
D.-3a2+5a-5b.
67.x3-5x2-4x+9等于 [ ]
A.(x3-5x2)-(-4x+9);
B.x3-5x2-(4x+9);
C.-(-x3+5x2)-(4x-9);
D.x3+9-(5x2-4x).
[ ]
69.4x2y-5xy2的结果应为 [ ]
A.-x2y;
B.-1;
C.-x2y2;
D.以上答案都不对.
(三)化简
70.(4x2-8x+5)-(x3+3x2-6x+2).
72.(0.3x3-x2y+xy2-y3)-(-0.5x3-x2y+0.3xy2).
73.-{2a2b-[3abc-(4ab2-a2b)]}.
74.(5a2b+3a2b2-ab2)-(-2ab2+3a2b2+a2b).
75.(x2-2y2-z2)-(-y2+3x2-z2)+(5x2-y2+2z2).
76.(3a6-a4+2a5-4a3-1)-(2-a+a3-a5-a4).
77.(4a-2b-c)-5a-[8b-2c-(a+b)].
78.(2m-3n)-(3m-2n)+(5n+m).
79.(3a2-4ab-5b2)-(2b2-5a2+2ab)-(-6ab).
80.xy-(2xy-3z)+(3xy-4z).
81.(-3x3+2x2-5x+1)-(5-6x-x2+x3).
83.3x-(2x-4y-6x)+3(-2z+2y).
84.(-x2+4+3x4-x3)-(x2+2x-x4-5).
85.若A=5a2-2ab+3b2,B=-2b2+3ab-a2,计算A+B.
86.已知A=3a2-5a-12,B=2a2+3a-4,求2(A-B).
87.2m-{-3n+[-4m-(3m-n)]}.
88.5m2n+(-2m2n)+2mn2-(+m2n).
89.4(x-y+z)-2(x+y-z)-3(-x-y-z).
90.2(x2-2xy+y2-3)+(-x2+y2)-(x2+2xy+y2).
92.2(a2-ab-b2)-3(4a-2b)+2(7a2-4ab+b2).
94.4x-2(x-3)-3[x-3(4-2x)+8].
(四)将下列各式先化简,再求值
97.已知a+b=2,a-b=-1,求3(a+b)2(a-b)2-5(a+b)2×(a-b)2的值.
98.已知A=a2+2b2-3c2,B=-b2-2c2+3a2,C=c2+2a2-3b2,求(A-B)+C.
99.求(3x2y-2xy2)-(xy2-2x2y),其中x=-1,y=2.
101.已知|x+1|+(y-2)2=0,求代数式5(2x-y)-3(x-4y)的值.
106.当P=a2+2ab+b2,Q=a2-2ab-b2时,求P-[Q-2P-(P-Q)].
107.求2x2-{-3x+5+[4x2-(3x2-x-1)]}的值,其中x=-3.
110.当x=-2,y=-1,z=3时,求5xyz-{2x2y-[3xyz-(4xy2-x2y)]}的值.
113.已知A=x3-5x2,B=x2-6x+3,求A-3(-2B).
(五)综合练习
115.去括号:{-[-(a+b)]}-{-[-(a-b)]}.
116.去括号:-[-(-x)-y]-[+(-y)-(+x)].
117.已知A=x3+6x-9,B=-x3-2x2+4x-6,计算2A-3B,并把结果放在前面带“-”号的括号内.
118.计算下式,并把结果放在前面带“-”号的括号内:
(-7y2)+(-4y)-(-y2)-(+5y)+(-8y2)+(+3y).
119.去括号、合并同类项,将结果按x的升幂排列,并把后三项放在带有“-”号的括号内:
120.不改变下式的值,将其中各括号前的符号都变成相反的符号:(x3+3x2)-(3x2y-7xy)+(2y3-3y2).
121.把多项式4x2y-2xy2+4xy+6-x2y2+x3-y2的三次项放在前面带有“-”号的括号内,二次项放在前面带有“+”号的括号内,四次项和常数项放在前面带有“-”号的括号内.
122.把下列多项式的括号去掉,合并同类项,并将其各项放在前面带有“-”号的括号内,再求2x-2[3x-(5x2-2x+1)]-4x2的值,其中x=-1.
123.合并同类项:
7x-1.3z-4.7-3.2x-y+2.1z+5-0.1y.
124.合并同类项:5m2n+5mn2-mn+3m2n-6mn2-8mn.
126.去括号,合并同类项:
(1)(m+1)-(-n+m);
(2)4m-[5m-(2m-1)].
127.化简:2x2-{-3x-[4x2-(3x2-x)+(x-x2)]}.
128.化简:-(7x-y-2z)-{[4x-(x-y-z)-3x+z]-x}.
129.计算:(+3a)+(-5a)+(-7a)+(-31a)-(+4a)-(-8a).
130.化简:a3-(a2-a)+(a2-a+1)-(1-a4+a3).
131.将x2-8x+2x3-13x2-2x-2x3+3先合并同类项,再求值,其中x=-4.
132.在括号内填上适当的项:[( )-9y+( )]+2y2+3y-4=11y2-( )+13.
133.在括号内填上适当的项:
(-x+y+z)(x+y-z)=[y-( )][y+( )].
134.在括号内填上适当的项:
(3x2+xy-7y2)-( )=y2-2xy-x2.
135.在括号内填上适当的项:
(1)x2-xy+y-1=x2-( );
(2)[( )+6x-7]-[4x2+( )-( )]=x2-2x+1.
136.计算4x2-3[x+4(1-x)-x2]-2(4x2-1)的值.
137.化简:
138.用竖式计算
(-x+5+2x4-6x3)-(3x4+2x2-3x3-7).
139.已知A=11x3+8x2-6x+2,B=7x3-x2+x+3,求2(3A-2B).
140.已知A=x3-5x2,B=x3-11x+6,C=4x-3,求
(1)A-B-C;
(2)(A-B-C)-(A-B+C).
141.已知A=3x2-4x3,B=x3-5x2+2,计算
(1)A+B;
(2)B-A.
142.已知x<-4,化简|-x|+|x+4|-|x-4|.
146.求两代数式-1.56a+3.2a3-0.47,2.27a3-0.02a2+4.03a+0.53的差与6-0.15a+3.24a2+5.07a3的和.
-0.3,y=-0.2.
150.已知(x-3)2+|y+1|+z2=0,求x2-2xy-5x2+12xz+3xy-z2-8xz-2x2的值.
这个自己弄吧,兄弟,这里就算有也都是在网上随便复制的骗分的!~
绛旓細2(a-b)2-5(a+b)2脳(a-b)2鐨勫硷紟 98锛庡凡鐭=a2+2b2-3c2,B=-b2-2c2+3a2,C=c2+2a2-3b2,姹(A-B)+C锛 99锛庢眰(3x2y-2xy2)-(xy2-2x2y),鍏朵腑x=-1,y=2锛 101锛庡凡鐭x+1|+(y-2)2=0,姹備唬鏁板紡5(2x-y)-3(x-4y)鐨勫硷紟 106锛庡綋P=a2+...
绛旓細48锛9a2+[7a2-2a-(-a2+3a)]=___锛50锛庡綋2y-x=5鏃,5(x-2y)2-3(-x+2y)-100=___锛
绛旓細1銆-9(x-2)-y(x-5)锛1锛鍖栫畝鏁翠釜寮忓瓙.锛2锛夊綋x=5鏃,姹倅鐨勮В.2銆5(9+a)脳b-5(5+b)脳a 锛1锛夊寲绠鏁翠釜寮忓瓙.锛2锛夊綋a=5/7鏃,姹傚紡瀛愮殑鍊.3銆62g+62(g+b)-b 锛1锛夊寲绠鏁翠釜寮忓瓙.锛2锛夊綋g=5/7鏃,姹俠鐨勮В.4銆3(x+y)-5(4+x)+2y 锛1锛夊寲绠鏁翠釜寮忓瓙.5銆(x+y)(x...
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绛旓細1銆-9(x-2)-y(x-5) 锛1锛鍖栫畝鏁翠釜寮忓瓙.锛2锛夊綋x=5鏃,姹倅鐨勮В.2銆5(9+a)脳b-5(5+b)脳a 锛1锛夊寲绠鏁翠釜寮忓瓙.锛2锛夊綋a=5/7鏃,姹傚紡瀛愮殑鍊.3銆62g+62(g+b)-b 锛1锛夊寲绠鏁翠釜寮忓瓙.锛2锛夊綋g=5/7鏃,姹俠鐨勮В.4銆3(x+y)-5(4+x)+2...
绛旓細13.鍏堝寲绠,鍐嶆眰鍊 (4x-3y)鐨勫钩鏂-(3x-2y)(3x+2y),鍏朵腑x=2,y=1 14.鍖栫畝姹傚锛氾紙1 + a - 5a锛-锛- a +2a 锛,鍏朵腑a= - 3 15.宸茬煡3鍒嗕箣a=4鍒嗕箣b=5鍒嗕箣c,姹備唬鏁板紡2b-a鍒嗕箣2a+b+c鐨勫 16.锛坸锛3锛2锛媩y锛2|=0鍒檡x鐨勫间负锛 锛17.璁綼,b,c涓烘湁鐞嗘暟,涓攟a|+a=0...
绛旓細鍖栭棿姹傚: 涓嬮潰鐨勪綘鑷繁姹傚惂``` 1銆-9(x-2)-y(x-5) (1)鍖栫畝鏁翠釜寮忓瓙. (2)褰搙=5鏃,姹倅鐨勮В. 2銆5(9+a)脳b-5(5+b)脳a (1)鍖栫畝鏁翠釜寮忓瓙. (2)褰揳=5/7鏃,姹傚紡瀛愮殑鍊. 3銆62g+62(g+b)-b (1)鍖栫畝鏁翠釜寮忓瓙. (2)褰揼=5/7鏃,姹俠鐨勮В. 4銆3(x+y)-5(4+x)+2y (1)鍖栫畝...
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绛旓細[(a+1/2b)²+(a-1/2b)²]路锛2a²-1/2b²锛=(a²+ab+1/4b²+a²-ab+1/4b²)(2a²-1/2b²)=(2a²+1/2b²)(2a²-1/2b²)=(18+8)(18-8)=26脳10 =260 ...
绛旓細鏁村紡鍖栫畝姹傚奸鍙婄瓟妗 绠鍗曚竴鐐癸紝鍘诲垎姣嶇殑鏂圭▼涔熻锛岃鏈夌瓟妗堛傝秺澶氳秺濂斤紝鎴戞湁杩藉姞 ,鏈濂芥槸鍘熷垱鐨勶紝鍒嗘瘝鐨勬柟绋嬩篃鏉ョ偣銆傛潵鑷尶鍚嶇敤鎴风殑鎻愰棶 鏈浣崇瓟妗堢敱鎻愰棶鑰呮帹鑽 1.锛3X+2Y)+(4X+3Y)鍏朵腑X=5,Y+3 瑙o細鍘熷紡=3X+2Y+4X+3Y=7X+5Y 褰揦=5,Y=3鏃 鍘熷紡=5*7+锛-3锛*5+20 2.(5a^2-3b...