化简 2(xy-xy²+3)-(-4xy²+xy-1) 其中,x等于--4,y等于-3
(5xy-2x的平方)-3xy-2(3xy-4x的平方)其中x等于1,y等于-2?
化简求值:【4(xy-1)²-(xy+2)(2-xy)】÷¼xy,其中x=-3,y=1/5
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1
2xy-1/2(4xy-8x²y²)+2(3xy-5x²y²),其中x=3/2,
(xy^-1)²*(-xy^4)^-1*(-y²x^-1)³等于
化简并求值 xy-2{xy-[3x²y-(xy²+0.5xy)]+4x²y},其中x=1,
3x²y+xy²-[2xy²-4x²y+(x²y-2xy²)
计算 2xy[4x²y²-3y(xy+x²y)-xy²]
(1)先化简,再求值:[4(xy-1)²-(xy+2)(2-xy)]÷1/4xy,其中x=-2,y=1/5.
化简求值 已知:(x+2)2;+|y+1|=0求5xy²-{2xy²-[3xy²(4xy&
求3x²y-2xy²+2(xy-二分之三x²y)-xy+3xy²的值,其中x=3
化简!1、(x^2-xy)+xy+y^2 2、3(x^2-xy)-xy+y^2