x+80%y=42 y-x=12

x+80%y=42 y-x=12 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)(x*x+y*y)-(x*x+y*y)=12 求x*x+y*y等于多少 x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 x.y都是自然数,且x(x-u)-y(y-x)+12,求x.y得值快1且x(x-y)-y(y-x)=12 {80/(x+y) +42/(x-y) =7 40/(x+y) +70/(x-y) =7 怎么解( ⊙ o ⊙ {80/(x+y) +42/(x-y) =7 40/(x+y) +70/(x-y) =7 快 急 解方程组80/x+y + 42/x-y=7 40/x+y + 7/x-y=7非常感谢! [(y*y*y-y)/(xy+1)*(xy+1)-(x+y)*(x+y)]/[(x+y)*y/(x+1)]其中x=-11,y=1/12,化简再求值. 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,Y) f(x,y)={12y^2,0 12y(x-y)^2-8(x-y)^3=? 已知|x|+x+y=10 |y|+x-y=12 求 x+y=? 已知|x|+x+y=10,|y|+x-y=12,求x+y的值 已知|x|+x+y=10,x+|y|-y=12,求x、y的值 Y-X=45 (80%Y-X)×8=(Y-35-X)×12