(3a+b)4b-[(2a+b+a-b)b]/2
问题描述:
(3a+b)4b-[(2a+b+a-b)b]/2
答
原式=(12ab+4b^2)-(3a)b/2
=12ab+4b^2-3ab/2
=(12-3/2)ab+4b^2
=21ab/2+4b^2