计算(a-2b)(a^2-3ab+b^2)?

问题描述:

计算(a-2b)(a^2-3ab+b^2)?

原式=a(a^2-3ab+b^2)-2b(a^2-3ab+b^2)
=a³-3a²b+ab²-2a²b+6ab²-2b³
=a³-5a²b+7ab²-2b³