(2a+b)^2-(3a-b)^2+5a(a-b)

问题描述:

(2a+b)^2-(3a-b)^2+5a(a-b)

(2a+b)²-(3a-b)²+5a(a-b)
=4a²+4ab+b²-(9a²-6ab+b²)+5a²-5ab
=4a²+4ab+b²-9a²+6ab-b²+5a²-5ab
=5ab