1.(a-b)(a²-ab+b²)-ab(b-a)
5个回答

1.(a-b)(a²-ab+b²)-ab(b-a)

=(a-b)(a²-ab+b²)+ab(a-b)

=(a-b)(a²-ab+b²+ab)

=(a-b)(a²+b²)

2.(7a-8b)(a-2b)+(a-8b)(a-2b)

=(a-2b)[(7a-8b)+(a-8b)]

=(a-2b)(8a-16b)

=8(a-2b)²

3.x²-xy-2y²

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

4.(m-n)²-(m-n)-12

=[(m-n)+3][(m-n)-4]

=(m-n+3)(m-n-4)

5.-2a五次方b平方+8a四次方b-8a三次方

=-2a^3(a²b²-4ab+4)

=-2a^3(ab-2)²