Question

a的三次方减去b的三次方是多少,结果化简

Answer 1

a^3-b^3

=a^3+a^2b-a^2b+ab^2-ab^2-b^3

=(a-b)a^2+(a-b)ab+(a-b)b^2

=(a-b)(a^2+ab+b^2)