Question

16（a-b)^2-9(a+b)^2和3(x-y)^3+12(y-x)这两道题怎样因式分解

Answer 1

16（a-b)^2-9(a+b)^2

=[4(a-b)+3(a+b)]*[4(a-b)-3(a+b)]

=(7a-b)(a-7b)

3(x-y)^3+12(y-x)

=3(x-y)^3-12(x-y)

=3(x-y)[(x-y)^2-4]

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