已知(x+y)/(x-y)=3/2,则(x²+y²)/xy =

已知2x=3y,则y分之x=< >,y分之x+y=< >. 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知|x+y-3|+(x-y)2=0则 比例线段：已知x/y=2/3,则 x/x+y= ,x-y/x+y= 要过程! 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 已知3x =2y 求x/x+y+y/x-y-y²/x²-y² 已知方程组{(X+Y)-3(X-Y)=7,2(X+Y)+(X-Y）=-7}则(X+Y)(X-Y)= 已知f(x+y,y/x)=x^2-y^2,则f(x,y)= 已知x/5=y/3,则(x/x+y)+(y/x-y)-(yxy/xxx-yxy) 已知|x|=2,|y|=3,|x+y|=-(x+y)求x-y 已知x+2y=3则x=? x-y=7则y=? 已知x-2y=3,则(2x+y-6)/(3x-y-9)=? 已知2x-3y=0则3x-y比x+2y= 已知x-y=3则5(x-y)-3x+3y-2= 已知x-y=3则5(x-y)-3x+3y-2= 已知(3x+y+6)²+|x+y+2|=2,则x=,y=. 已知x^2-3xy+2y^2=0 则x/y+x/y= 已知3x-4y=0,则x^2-y^2/x^2+y^2