分解因式9(a-b)(a+b)-3(a-b)^2
1个回答

(1)9(a-b)(a+b)-3(a-b)^2

=3(a-b)[3(a+b)-(a-b)]

=3(a-b)(3a+3b-a+b)

=3(a-b)(2a+4b)

=6(a-b)(a+2b)

(2)-2(b-2a)^2 +(b-2a)

=(b-2a)[-2(b-2a)+1]

=(b-2a)(4a-2b+1)

(3) 3(x+y)(y-x)-(x-y)^2

=3(x+y)(y-x)-(y-x)^2

=(y-x)[3(x+y)-(y-x)]

=(y-x)(3x+3y-y+x)

=(y-x)(4x+2y)

=2(y-x)(2x+y)

(4) -3(x-y)^2-(y-x)^3

=-3(x-y)^2+(x-y)^3

=(x-y)²(-3+x-y)