化简求值题及答案40道 求40道分式的化简求值题。急！
\u5316\u7b80\u6c42\u503c\u9898\u53ca\u7b54\u6848100\u90531.\uff083X+2Y)+(4X+3Y)\u5176\u4e2dX=5,Y+3
\u89e3\uff1a\u539f\u5f0f=3X+2Y+4X+3Y=7X+5Y
\u5f53X=5,Y=3\u65f6
\u539f\u5f0f=5*7+\uff08-3\uff09*5+20
2.(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
1.\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
\u6574\u5f0f\u5316\u7b80\u6c42\u503c\u9898\u53ca\u7b54\u6848
\u7b80\u5355\u4e00\u70b9\uff0c\u53bb\u5206\u6bcd\u7684\u65b9\u7a0b\u4e5f\u884c\uff0c\u8981\u6709\u7b54\u6848\u3002
\u8d8a\u591a\u8d8a\u597d\uff0c\u6211\u6709\u8ffd\u52a0 ,\u6700\u597d\u662f\u539f\u521b\u7684\uff0c\u5206\u6bcd\u7684\u65b9\u7a0b\u4e5f\u6765\u70b9\u3002
\u6765\u81ea\u533f\u540d\u7528\u6237\u7684\u63d0\u95ee
\u6700\u4f73\u7b54\u6848\u7531\u63d0\u95ee\u8005\u63a8\u8350
1.\uff083X+2Y)+(4X+3Y)\u5176\u4e2dX=5,Y+3
\u89e3\uff1a\u539f\u5f0f=3X+2Y+4X+3Y=7X+5Y
\u5f53X=5,Y=3\u65f6
\u539f\u5f0f=5*7+\uff08-3\uff09*5+20
2.(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
3.2(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
1\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
2.
3ab-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
1、例题：2(2a²+2ab)-(3a²+4ab-b²)，其中a=2，b=-1
解：原式=2a²+4ab-3a²-4ab+b²
=b²-a²
=1-4
=-3
2、例题：1/4(a+b)²-6(a-b)+3/4(a+b)²+6(a-b)，其中a=2，b=-1
解：原式=(a+b)²
3、例题：5(a-b)²-3(a-b)²-7(a-b)-(a-b)²+7(a-b)，其中a=2，b=-1
解：原式=(a-b)²
=3²
=9
4、例题：1/2a²-1/4b+3/2a²-3/4b-a²，其中a=2，b=-1
解：原式=2a²-b-a²
=a²-b
=4+1
=5
5、例题：-5yx²+4xy²-2xy+6x²y+2xy+5，其中x=2，y=-1
解：原式=x²y+4xy²+5
=-4-8+5
=-7
扩展资料：
化简求值解题技巧：
1、顺序化简。在做题时一定要做到先化简再求值，按照题目的要求来做；化简过程中一定要按着分式化简的运算法则来进行，化简的结果一定要最简，像这种直接带值进去计算的题目，往往都牵扯到无理数的计算，一定要注意掌握分母有理化的方法。
2、换元法。根据已知条件，利用未知变量替换有规律表达式，寻找规律，快速求解。
3、整体代入法。由已知条件，通过加减乘除运算，得到与求解表达式相关的表达数值，整体代入。
4、配方法。通过一系列变形、化简、凑元，将所求配成公式，利用公式进行求解。
化简求值题及答案推荐如下：
1、已知A,B是方程x^2+2x-5=0的两个实数根,
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+6x² -3(x-2/3x²)
=9x+6x²-3x+2x²
=8x²+6x
=8×(-2)²+6×(-2)
=32-12
=20
6、1/4(-4x^2+2x-8)-(1/2x-1),其中x=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、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
解析：
(√a-√b)²+(√a+√b)²
=(a+b-2√a√b)+(a+b+2√a√b)
=2(a+b)
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