Question

计算（1）a²（a-1）+(a-5)(a+7)（2）(x-5y)²-(x+5y)²

要答案和计算过程

Answer 1

(1).
=a^3-a^2+a^2+7a-5a-35
=a^3+2a-35
(2).
=x^2-10xy+25y^2-(x^2+10xy+25y^2)
=-20xy