y+x+x+x=53,x+y=21 (x=16 x=32)y-x-x-x=53,y-x=69(x=16 x=8)y-x+x+x=53,y-x=21(x=16 x=32) 从括号中选一个值

y=x(x 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+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=? x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 x+x+x+x+y+y+y=56 y+x+x+x=53,y-x=21 (x=16 x=32)y+x+x+x=53,y-x=21 (x=16 x=32) x的值是多少? x+x+x+y+y=21,x+x+x+x+x+y+y=27,求x=?y=? 推倒公式:(x+y)(x*x-3x+y*y)=x*x*x+y*y*y怎么做. x+x+x+y+y=6.4 y+y+y+x+x=7.1 怎么算? x+x+x+y=60 .x-y=4 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) （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 x+x=y+30