已知15x^2-47xy+28y^2=0
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*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方
已知x-2 根号xy - 15y = 0 ,求 2x+ 根号xy +3y╱x+根号xy - y
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
已知x+2y=0,求分式2xy+y^2/x^2-xy
已知实数xy满足x²﹢y²-xy+2x-y+1=0求xy
已知x²-7xy+12y²=0求x²-xy+y²/2xy的值
已知x-y=4xy,则2x+3xy-2yx-2xy-y
已知:xy+x=-1,xy-y=-2.
已知x-xy=8,xy-y=-9,求x+y-2xy的值
已知3x^2+xy-2y^2=0,求{(x+y)/(x-y)+4xy/(y^2-x^2)}/{(x+3y)*(x-y)}