化简:(2x-y)(2x+y)+(x+y)(x-2y)=_.
问题描述:
化简:(2x-y)(2x+y)+(x+y)(x-2y)=______.
答
原式=4x2-y2+x2-2xy+xy-2y2
=5x2-xy-3y2.
故答案为:5x2-xy-3y2.