x-2+y=100求Xy

x-2+y=100求Xy 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 x+y=100 求xy y'=-2xy;求f(x). 3X^2+XY+Y=15 求XY. 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 如果x^2+xy+y-14,y^@+xy+x=28,求x+y的值. f(xy,x-y)=x^2-xy+y^2.求f(x,y) 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 x+y+2xy=83求x+y=? x^2-y^2=xy 求x/y, 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) xy^2-e^x+e^y=1 求y' 是xy^2 不是xy