(2a+b)*(2a+3b)-3a*2b等于多少

问题描述:

(2a+b)*(2a+3b)-3a*2b等于多少

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