初一 数学 因式分解 请详细解答,谢谢! (25 16:10:8)

1. (m-n)3+2n(n-m)2
=(m-n)^3+2n(m-n)^2
=(m-n)^2(m-n+2n)
=(m-n)^2(m+n)

2. (2x2-2x+1/2)/(x-1/2)
=(4x^2-4x=1)/(2x-1)
=(2x-1)^2/(2x-1)
=2x-1

3. 已知a+b=-2,ab=-5/2.求a(a+b)(a-b)-a(a+b)2的值
a(a+b)(a-b)-a(a+b)2
=(a+b)(a^2-ab-a^2-ab)
=-2(a+b)ab
=-2*(-2)*(-5/2)
=-10

4. 解方程 （3y+5)2=4y2

3y+5=2y y=-5
3y+5=-2y y=-1

1.
(m-n)^3+2n(n-m)^2
=(m-n)^3+2n(m-n)^2
=(m-n)^2[(m-n)+2n]
=(m-n)^2(m-n+2n)
=(m-n)^2(m+n)

2.
(2x^2-2x+1/2)/(x-1/2)
=[2(x^2-x+1/4)]/(x-1/2)
=[2(x-1/2)^2]/(x-1/2)
=2(x-1/2)
=2x-1

3.
a(a+b)(a-b)-a(a+b)^2
=a(a+b)[(a-b)-(a+b)]
=a(a+b)(a-b-a-b)
=a(a+b)(-2b)
=(a+b)(-2ab)
=(-2)(-2*-5/2)
=(-2)*5
=-10

4.
(3y+5)^2=4y^2
(3y+5)^2-4y^2=0
[(3y+5)-2y][(3y+5)+2y]=0
(3y+5-2y)(3y+5+2y)=0
(y+5)(5y+5)=0
y1=-5,y2=-1

1. (m-n)^3+2n(n