(-2ab^2)^2(-ab)^3?

Question

i know that the answer is -4a^5b^7, but how do i get it

Answer 1

(-2ab^2)^2(-ab)^3 = (4 a^2 b^4) * (-1 * a^3 b^3)
= -4 (a^2 * a^3) * (b^4 * b^3)
= -4 (a^5) (b^7)