化简求值:2(x2y+xy)-3(x2y-xy)-4x2y,其中x=-1,y=1.
网友回答
原式=2x2y+2xy-3x2y+3xy-4x2y=-5x2y+5xy,
当x=-1,y=1时,
原式=-5×(-1)2×1+5×(-1)×1=-5-5=-10.
======以下答案可供参考======
供参考答案1:
2(x²y+xy)-3(x²y-xy)-4x²y
=2x²y+2xy-3x²y+3xy-4x²y
=-5x²y+5xy
=-5xy(x-1)
=-5*(-1)*1*(-1-1)
=5*(-2)
=-10不懂可追问,有帮助请采纳,谢谢!