化简:(2x-y)(2x+y)+(x+y)(x-2y)=______.

2025-06-22 12:41:55
推荐回答(1个)
回答1:

原式=4x 2 -y 2 +x 2 -2xy+xy-2y 2
=5x 2 -xy-3y 2
故答案为:5x 2 -xy-3y 2