因式、整式计算,急1.(a^2+b/a^2-b^2-a-b/a+b)*a-b/2ab2.若a^m=2,a^m=3,求a^3m+2n的值3.计算(-x)^5*(-x)^2(-2ab^2)/(-b^2)^2-2a(a^2b^2-1)(3a^6x^3-9ax^5)/(-3ax^3)4(x+y)(x-y)-(2x+y)^2(2x-5)(x+5)-(3x-4)(4-3x)4.若-2a^2m-1b^2与ab^n-3的和仍

Question

因式、整式计算,急
1.(a^2+b/a^2-b^2-a-b/a+b)*a-b/2ab
2.若a^m=2,a^m=3,求a^3m+2n的值
3.计算 (-x)^5*(-x)^2
(-2ab^2)/(-b^2)^2 -2a(a^2b^2-1)
(3a^6x^3-9ax^5)/(-3ax^3)
4(x+y)(x-y)-(2x+y)^2
(2x-5)(x+5)-(3x-4)(4-3x)
4.若-2a^2m-1 b^2 与 ab^n-3的和仍是单项式,则m+n
5.已知x^2-4,求代数式x(x+1)^2-x(x^2+x)-x-7的值
6.因式分解 x^2(x-y)-y^2(x-y)
x^2+2xy-3y^2

Answer 1

1,
[(a^2+b^2)/(a^2-b^2)-(a-b)/(a+b)]*(a-b)/(2ab)
=[(a^2+b^2)/(a+b)(a-b)-(a-b)^2/(a+b)(a-b)]*(a-b)/(2ab)
=[(a^2+b^2-a^2+2ab-b^2]/(a+b)(a-b)*(a-b)/(2ab)
=2ab/(a+b)(a-b)*(a-b)/(2ab)
=1/(a+b)
2,
a^m=2,a^m=3,
a^(3m+2n)
=a^3m*a^2n
=(a^m)^3*(a^n)^2
=2^3*3^2
=8*9=72.
3,
(-x)^5*(-x)^2=-x^7
(-2ab^2)/(-b^2)^2)=-2a/b^2
-2a(a^2b^2-1)=-2a^3*b^2+2a
(3a^6x^3-9ax^5)/(-3ax^3)=-a^5+3x^2
4(x+y)(x-y)-(2x+y)^2=4(x^2-y^2)-(4x^2+4xy+y^2)=-5y^2-4xy
(2x-5)(x+5)-(3x-4)(4-3x)=(2x^2+5x-25)-(-9x^2+24x-16)=11x^2-19x-9
4,
-2a^(2m-1)*b^2+ab^(n-3)仍是单项式
2m-1=1,n-3=2
m=1,n=5
m+n=6
5,
x^2=4
x(x+1)^2-x(x^2+x)-x-7
=x[(x+1)^2-(x^2+x)]-x-7
=x[x^2+2x+1-x^2-x]-x-7
=x(x+1)-x-7
=x^2+x-x-7
=x^2-7
=4-7
=-3
6,
x^2(x-y)-y^2(x-y)=(x-y)(x^2-y^2)=(x-y)^2(x+y)
x^2+2xy-3y^2=(x+3y)(x-y)