Question

已知a-b=5,ab=4,那么a^3b-2a^2b^2=ab^3等于

Answer 1

a^3b-2a^2b^2=ab^3后面的=应该是+号吧.

a^3b-2a^2b^2+ab^3=ab(a^2-2ab+b^2)=ab(a^2-2ab+b^2)=ab(a-b)^2= 4*5^2=100