因式分解，解方程组，化简求值（或计算）各50题 求七下数学50题计算，50题解不等式，50题因式分解，50题...
\u56e0\u5f0f\u5206\u89e3\uff0c\u89e3\u65b9\u7a0b\u7ec4\uff0c\u5316\u7b80\u6c42\u503c\uff08\u6216\u8ba1\u7b97\uff09\u540450\u98981\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
\u5988\u86cb\uff0c\u8fd9\u8001\u5e08\u8be5\u7f5a\u53bb\u6361\u80a5\u7682\u3002\u8fd9\u6bd4\u4f53\u7f5a\u8fd8\u6076\u5fc3\uff01
因式分解：（1）.3y²-5xy-2y=(3x+y)(x-2y)
（2）.x³-5x²+6x=x(x-2)(x-3)
（3）.a²+2a+1-b²=(a+1)²-b²=(a+b+1)(a-b+1)
（4）.（x²-2x）²+2（x²-2x）+1=[(x²-2x)+1]²=[(x-1)²]²=(x-1)^4
化简并求值：
（2a+b）²-（3a-b）²+5a（a-b）,其中a=1,b=五分之一
（2a+b）²-（3a-b）²+5a（a-b）
=4a²+4ab+b²-(9a²-6ab+b²)+5a²-5ab
=5ab
=5×1×1/5
=1
绛旓細鍥犲紡鍒嗚В锛氾紙1锛.3y²-5xy-2y=(3x+y)(x-2y)锛2锛.x³-5x²+6x=x(x-2)(x-3)锛3锛.a²+2a+1-b²=(a+1)²-b²=(a+b+1)(a-b+1)锛4锛.锛坸²-2x锛²+2锛坸²-2x锛+1=[(x²-2x)+1]²=[(x-1)&#...
绛旓細3.鍥犲紡鍒嗚Вxy+6-2x-3y=(x-3)(y-2) 4.鍥犲紡鍒嗚Вx2(x-y)+y2(y-x)=(x+y)(x-y)^2 5.鍥犲紡鍒嗚В2x2-(a-2b)x-ab=(2x-a)(x+b) 6.鍥犲紡鍒嗚Вa4-9a2b2=a^2(a+3b)(a-3b) 7.鑻ュ凡鐭3+3x2-4鍚湁x-1鐨勫洜寮,璇曞垎瑙3+3x2-4=(x-1)(x+2)^2 8.鍥犲紡鍒嗚Вab(x2-y2)+xy(a2-b2)...
绛旓細1,3x'y-[2x'y-(2xyz-x'z)-4x'z]-xyz,鍏朵腑x=-2,y=-3,z=1,鍘熷紡=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 褰搙=2,y=3,z=1鏃 鍘熷紡=4*(-3)-2*3*1+3*4*1 =-12-6+12 =-6 2,3X+2Y)+(4X+3Y)鍏朵腑X=5,Y...
绛旓細瑙ｏ細鍘熷紡=锛9x²-6xy+y²锛-(8x²-10xy)-(x²+4xy+4y²)=9x²-6xy+y²-8x²+10xy-x²-4xy-4y²=-3y²褰搙=2009,y=-2鏃 -3y²=-3*锛-2锛²=-12 2.鍏鍖栫畝锛鍐姹傚 -2x-{4x-2y-[3x-(2y+1)},鍏朵腑x...
绛旓細²=[(x-1)²]²=(x-1)^4 鍖栫畝骞姹傚锛氾紙2a+b锛²-锛3a-b锛²+5a锛坅-b锛,鍏朵腑a=1,b=浜斿垎涔嬩竴 锛2a+b锛²-锛3a-b锛²+5a锛坅-b锛=4a²+4ab+b²-(9a²-6ab+b²)+5a²-5ab =5ab =5脳1脳1/5 =1 ...
绛旓細1.鍖栫畝(1-1/x-1)/(x/x^-1)鍦ㄩ夋嫨涓涓傚綋鐨剎姹傚 瑙(1-1/(x-1))/(x/(x^-1))=((x-2)/(x-1))/(x/(x+1)(x-1))=(x-2)/(x-1)*(x+1)(x-1)/x =(x-2)(x+1)/x 褰搙=2鏃讹紝鍘熷紡=0 x閫傚綋鐨勫间竴瀹氫笉鑳芥槸1锛-1锛0 2.銆1/2(x+y+z)鏂+1/2(x-y-z...
绛旓細=4mn 锛堬紙x^2-2x锛/x-2銆暶穢+锛坸^2-1锛/锛坸^2-2x+1锛=(x-2-2)梅x+(x-1)(x+1)/(x-1)^2 =(x-4)梅x+锛坸+1)/(x-1)鍥犱负x锛1/2锛屽甫鍏ュ叕寮忓緱锛=2(1/2-4)+(1/2+1)/(1/2-1)=(1-8)+(3/2锛/(-1/2)=-7-3 =-10 鑻-2鏄湁鎷彿鐨勶細[锛坸^2-2x锛...
绛旓細1銆鍖栫畝姹傚:6x鐨勫钩鏂-(2x+1)(3x-2)+(x+3)(x-3),鍏朵腑x=2鍒嗕箣涓锛堣杩囩▼锛夎В锛氬師寮=6x^2-(6x^2-x-2)+x^2-9=x^2+x-7褰搙=1/2鏃讹紝鍘熷紡=1/4+1/2-7=-25/42銆鍥犲紡鍒嗚В锛-4a鐨勫钩鏂+24a-36锛堣杩囩▼锛夎В锛氬師寮=-4(a^2-6a+9)=-4(a-3)^23銆佺畝渚胯绠楋細10.5脳9.5...
绛旓細(x-y)(-y-x)-(3x^3y- 6x^2y^2 -3xy^3)梅(-3xy)=-(x-y)(x+y)-3xy(x^2-2xy+y^2)/(-3xy)=-(x+y)(x-y)+(x-y)^2 =(x-y)(-y-x+x-y)=-2y(x-y)甯﹀叆锛歺=1/2,y=-1 寰楋細=-2*(-1)*[1/2-(-1)]=3 ...
绛旓細1.鍖栫畝(1-1/x-1)/(x/x^-1)鍦ㄩ夋嫨涓涓傚綋鐨剎姹傚 瑙(1-1/(x-1))/(x/(x^-1))=((x-2)/(x-1))/(x/(x+1)(x-1))=(x-2)/(x-1)*(x+1)(x-1)/x =(x-2)(x+1)/x 褰搙=2鏃,鍘熷紡=0 x閫傚綋鐨勫间竴瀹氫笉鑳芥槸1,-1,0 2.銆1/2(x+y+z)鏂+1/2(x-y-z)...
