初一上册数学 代数式求值 的题?
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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=______.
1.(4x2-8x+5)-(x3+3x2-6x+2).
2.(0.3x3-x2y+xy2-y3)-(-0.5x3-x2y+0.3xy2).
3.-{2a2b-[3abc-(4ab2-a2b)]}.
4.(5a2b+3a2b2-ab2)-(-2ab2+3a2b2+a2b).
5.(x2-2y2-z2)-(-y2+3x2-z2)+(5x2-y2+2z2).
6.(3a6-a4+2a5-4a3-1)-(2-a+a3-a5-a4).
7.(4a-2b-c)-5a-[8b-2c-(a+b)].
8.(2m-3n)-(3m-2n)+(5n+m).
9.(3a2-4ab-5b2)-(2b2-5a2+2ab)-(-6ab).
10.xy-(2xy-3z)+(3xy-4z).
11.(-3x3+2x2-5x+1)-(5-6x-x2+x3).
12.3x-(2x-4y-6x)+3(-2z+2y).
13. 4x-2(x-3)-3[x-3(4-2x)+8].
14.(-x2+4+3x4-x3)-(x2+2x-x4-5).
15.若A=5a2-2ab+3b2,B=-2b2+3ab-a2,计算A+B.
16.已知A=3a2-5a-12,B=2a2+3a-4,求2(A-B).
17.2m-{-3n+[-4m-(3m-n)]}.
18.5m2n+(-2m2n)+2mn2-(+m2n).
19.4(x-y+z)-2(x+y-z)-3(-x-y-z).
20.2(x2-2xy+y2-3)+(-x2+y2)-(x2+2xy+y2).
将下列各式先化简,再求值
1.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.
2.已知A=a2+2b2-3c2,B=-b2-2c2+3a2,C=c2+2a2-3b2,求(A-B)+C.
3.求(3x2y-2xy2)-(xy2-2x2y),其中x=-1,y=2.
4.已知|x+1|+(y-2)2=0,求代数式5(2x-y)-3(x-4y)的值.
5.当P=a2+2ab+b2,Q=a2-2ab-b2时,求P-[Q-2P-(P-Q)].
6.求2x2-{-3x+5+[4x2-(3x2-x-1)]}的值,其中x=-3.
7.当x=-2,y=-1,z=3时,求5xyz-{2x2y-[3xyz-(4xy2-x2y)]}的值.
8.已知A=x3-5x2,B=x2-6x+3,求A-3(-2B).
(1)已知一个两位数,个位数字为a-1,十位数字是个位数字的2倍少1,这个两位数 。
2、若 a – b =10,那么15 – a + b 的值是 。
3、若 A – (- 3x ) = x2 + 3x – 1 ,则 A=
4、若m-n=4,mn=-1,求(-2mn+2m+3n)-(3mn+2n-2m)-(m+4n+mn)的值。
5、一个关于字每x的二次三项式的二次项系数和常数项都是1,一次项系数是负二分之一,则这个二次三项式是 。
同求、、、、
初一上册数学 代数式求值 的题?视频
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