{10x+9y=493 x+y=52

{10x+9y=493 x+y=52 y+10x=x+y+9 10y+x=y+10x+27 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 化简 x / y(x+y) - y / x(x+y) = 已知y/x=9/10则(1-y/x)[x/(y-x)]? x+x+x+y=52 y+y+y+x=36求x x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 x+(9-8-y)=10 y+y-(9-8-y)=2 x-y=xx-9.9x xy=11y-1 y=? x=? x+y-xy=?x+(9-8-y)=10y+y-(9-8-y)=2x-y=xx-9.9xxy=11y-1 y=?x=?x+y-xy=? x+4y=9,x-4y=10 x+10y+9=10x+y怎么解 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+10x=x+y+9 10y+x=y+10x+27怎么做?六年级方程组！ 谁会解10x+y=6(x+y)+3 10y+x=4(x+y)+9 解方程组：{x(x+y+z)=6 {y(x+y+z)=9 {z(x+y+z)=10 y=x(x x+y=20,x-y=10,y= 解方程组：2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66