计算 (3x+2a)(x-2a-1)+2a(2a+1)

问题描述:

计算 (3x+2a)(x-2a-1)+2a(2a+1)

(3x+2a)(x-2a-1)+2a(2a+1)
=3x²-6ax-3x+2ax-4a²-2a+4a²+2a
=3x²-4ax-3x