A^2b*(ab^2)^2 ------------------ a^3 b^4 halp

(a^2b(ab^2)^2)/(a^3b^4)=(a^2b(a^2b^4))/(a^3b^4)=(a^4b^5)/(a^3b^4)=a^(4-3)b^(5-4)=ab