【(-2xy*4)*2】*3
3xy-3xy-xy+2yx
【(2+xy)(xy-2)-xy(xy+1)+4】/(-2xy) 一道计算题!
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1
3(x的2次方y+xy)-4(xy-2x的2次方y)-(-xy)化简
已知x+y=4,xy=-2,求代数式3(xy+2y)-(xy-6x)
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
已知x-y=4,xy=-2,求代数式(2x+3y-2xy)-(x+4+xy)-(3xy+2y-2x)的值
利用x-y=3^2009,xy=-3^2010,求代数式:(2x+3y-2xy)-(x+4y+xy)-(3xy+2y-2
化简求值 已知:(x+2)2;+|y+1|=0求5xy²-{2xy²-[3xy²(4xy&
化简求值:【4(xy-1)²-(xy+2)(2-xy)】÷¼xy,其中x=-3,y=1/5
已知2x²-3y²=xy,(xy≠0),求值(4xy-x²)/(xy+2y²)的