Question

1)5(a-b)²-(a+b)-(b-a)
2)a(a-b)²-(b-a)

Answer 1

5(a^2-2ab+b^2)-a-b-b+a=5(a^2-2ab+b^2)-2b=5a^2-10ab+5b^2-2b
a(a^2-2ab+b^2)-b+a=a^3-2a^2b+b^2a-b+a