(x+y-xy)/(x+y+2xy)=(y+z-2yz)/(y+z+3yz)=(z+x-3zx)/(z+x+4zx),且2/x=3/y=1/z,则xyz=?

|x|/x+y/|y|+xy/|xy|= （-3x^y+2xy)-( )=4x^+xy (XY-X^2)除以X-Y/XY=? x*x+xy=3,xy+y*y=2,则x*x+2xy+y*y=________? x^2-xy/xy-y^2约分 （x^2+xy/x-y)/（xy/x-y)计算 X²+2xy+y²/xy乘x²-2xy+y²/xy+y²= [-xy^2(2x+y)-8xy)-x^2y)]除以2xy=计算 已知x+y=1,xy=-2,则x²y+xy²-2xy 已知x-xy=8,xy-y=-9,求x+y-2xy的值 1-2/x+y=xy,4y+6x=xy.求xy的解? y/x=ln(xy) 求dy/dx(xy-y^2)/(xy+x^2) 当x-y=2xy时,求4x-3xy-4y/xy 若1/x-1/y=2,求3x-2xy-3y/x-xy-y的值3x-2xy-3y/x-xy-y 不好意思，是3x-2xy-3y/x-2xy-y 由已知x+y=-2,xy=3那么2(x+xy)-[(xy-3y)-x]-(-xy)等于多少? f(xy,x-y)=x^2+y^2+xy;f(x,y)/∂x;f(x,y)/∂y x^2+xy+x=36,y^2+xy+y=20,求x+y. 若x^2+xy+y=14,y^2+xy+x=28,求x+y