x-y=8 45/x=36/y x=?y=?

x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 化简 x / y(x+y) - y / x(x+y) = x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 Y+X+X=36 Y-X-X=8 X=?Y=? 若(X×X+Y×Y)(X×X+Y×Y-5)=36,则X×X+Y×Y＝ x+x+y+y+y=21 ,x+x+y+y+y+y+y=27 ,x ,y=? x+x+y+y+y=21 ,x+x+y+y+y+y+y=27 ,x ,y=? y=x(x x+x+x+y=52 y+y+y+x=36求x x-y=8 45/x=36/y x=?y=? x+x+x+x+y+y+y=56 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= (x+y)/y=8/3则x/y=__ y/x-y=___ (x+y)/y=8/3则x/y=__ y/x-y=___ Y-X=45 (85%Y-X)×8=(Y-35-X)×12 Y-X=45 (85%Y-X)×8=(Y-35-X)×12 x+x+x+y+y=6.4 y+y+y+x+x=7.1 怎么算? 二元函数f(x,y)=x+y/x-y,求f(y/x,x/y) x-y/x+y=(x-y)²/x²-y²（x≠y)