已知X/Y=2/7,求x^2-3XY+2Y^2/X^2-2XY+Y^2
已知x=3y,试求(x-y)^2+2xy-y^2/x^2+7xy+y^2
已知xy^2=-2求xy(2x^3y^7+5x^2y
已知3x*+xy-2y*=0,求(x/y)-(y/x)-(x*+y*)/(xy)的值.*是平方
已知3/(x-y)=1/xy 求(-x-2xy+y)/ (2x+3xy-2y)
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.
已知x-y=4xy,求x-2xy-y分之2x+3xy-2y的值!
已知x+y=3xy,求2x+2y-xy/x+y+2xy的值、
已知xy/x+y =3,求2x-3xy+2y/-x+3xy-y 的值.
已知xy/x+y=3,求2x-3xy+2y/-x+3xy-y的值
已知xy/x+y=3,求代数式2x-5xy+2y/x-3xy+y
已知3x=xy+3y,求2x+xy-2y/y-x-xy的值