x+y+z=26 x=y+1 2x-y+z=18求过程!

1.x+y+z=26 x-y=0 2x+z=y+18解方程组,要过程! 2.x-y=0 x-z=-1 x+y+2z=2 (x+y-z)(x-y+z)= 已知x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求代数式x2/(y+z)+y2/(x+z)+z2/ 已知实数x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求x2/(y+z)+y2/(z+x)+z2/( x+y+z=1 求xyz/(x+y)(y+z)(z+x)的最大值 x y z x+y--- = --- = ---- ----y+Z z+x x+y ,求 z 的值 .求 x+y---- x+y-z=6 x-3y+2z=0 3x+2y-z=0 求x、y、z 要过程 { x+y+z=2 x-z=-2 y+z=1的解（求过程） 如果,根号x-3+| y-2 |+z^2=2z-1 求 （x+z)^y 已知x+y-z/z=x-y+z/y=-x+y+z/x,且xyz不等于0,求分式[(x+y)(x+z)(y+z)]/xyz 若z分之x+y+z=y分之x-y+z=x分之-x+y+z,求xyz分之(x+y)(y+z)(z+x) y+z÷x=Z+X÷y=X+Y÷z,X+Y+Z不等0求X+Y-Z÷X+Y+z值