(10y+x)-(10x+y)=27 9(y-x)=27 求第一步到第二步的详细

y+10x=x+y+9 10y+x=y+10x+27 y+10x=x+y+9 10y+x=y+10x+27怎么做?六年级方程组！ 已知y/x=9/10则(1-y/x)[x/(y-x)]? 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=? （10x+y）-（10y+x）=27 x+10y+9=10x+y怎么解 x+4y=9,x-4y=10 {10x+9y=493 x+y=52 1.5（x+y）+3（x-y）=27（x+y）-3（x-y）=-62.x-y/7 - x+y/10 =1/22(x-y)-5(x+y)=3所谓细节决定成败, 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=? 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 f(x,y)=x*x*x+y*y*y-9xy+27极值 解方程组：2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66 解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66 解方程组 2x+y(y-2x)=9 (x+y)(x+y-3)=10十万火急!求解! x+y=20,x-y=10,y=