2(x²y+xy)-3(x²y一xy)-4x²y其中x=1，y=-1
展开全部
首先去掉括号化简
2（x²y+xy）-3（x²y-xy）-4x²y
=2x²y+2xy-3x²y+3xy-4x²y
=2x²y-3x²y-4x²y+2xy+3xy
=-5x²y+5xy
=5xy(-x+1)
=5(-1)(1)(-1+1)
=0
2（x²y+xy）-3（x²y-xy）-4x²y
=2x²y+2xy-3x²y+3xy-4x²y
=2x²y-3x²y-4x²y+2xy+3xy
=-5x²y+5xy
=5xy(-x+1)
=5(-1)(1)(-1+1)
=0
追问
谢谢😊
本回答被提问者采纳
已赞过
已踩过<
评论
收起
你对这个回答的评价是？
推荐律师服务：
若未解决您的问题，请您详细描述您的问题，通过百度律临进行免费专业咨询
