已只(x-2)^2+(y+3)^2=0 求xy的值 急!
已只x.y满足x^2+2y^2-2xy-xy+1=0,求x+2y的值.
若x+y-5xy=0,求(2x-3xy+2y)/(x+2xy+y)的值
已知y-x-2xy=0,求3x+xy-3y/y-xy-x的值
已知y-x-2xy=0,求(3x+xy-3y)\(y-xy-x)的值
已知3x+2y=0,求代数式x^2+xy-y^2/x^2-xy+y^2的值.(急!)
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方
已知xy^2=-2,求-xy(x^2y^5-xy^3-y)的值.
已知y=3xy+x,求代数式2x+5xy-2y/x-2xy-y的值(xy≠0)
已知x-y=4xy且xy≠0,求代数式-x-2xy+y分之2x+3xy-2y的值
若(y-x)/xy=3,求分式(2x+3xy-2y)/(x-2xy-y)的值
已知x-y/xy=3,求分式2x+3xy-2y/x-2xy-y的值.
已知X+Y=3XY,求2X+2Y-XY除以X+Y+2XY的值,要算理.