XY/(100-X)=3/20 , 2XY/(100-2X=2/5 怎么解?
化简:xy分之3x^2+2xy-xy分之2x^2-xy=
已知x^2-xy=5,xy-y^2=-3求3(x^2-xy)-xy+y^2
(-3x^y+2xy)-( )=4x^+xy
(x-2)(y+3)=xy (x-5)(y+2)=xy 解方程组
已知xy^2=-2,求-xy(x^2y^5-xy^3-y)的值.
已知xy^2=-2 求-xy(x^2y^5-xy^3-y)
由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少?
已知(x+1)²+|y-1|=0,求2(xy-5xy²)-(3xy²-xy)得值
先化简,再求值 ⒈2(Xy+Xy)-3(Xy-xy)-4Xy,其中X=1,y=-1
(8xy-3x平方)-5xy-2(3xy-2x平方),其中,x=2,y=-1
若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值
已知x+y分之xy=2,那么3x-5xy+3y分之3xy-x-y=