100x+10y+1z=18x+18y+18x 求:x、y、z各是几.
解方程组{x(x+y+z)=6,y(x+y+z)=12,z(x+y+z)=18
已知x+2y-z=8,2x-y+z=18 ,求8X+Y-Z的值
已知x:y:z=2:3:4,且x+y+z=18,求x,y,z的值
1、已知X/2=Y/3=Z/4,(1)求(X-Y+Z)/(X+Y+Z) (2)若2x+3y z=18,求x,y,z
{x+z+y=15 z+x+w=18} {y+x+w=16 w+z+y=17} ,求x.y.z.w各是多少?
若2分之x+y=3分之y+z=5分之x+z 且x+y+z=18 求x,y,z的值
x+y+z=1 求xyz/(x+y)(y+z)(z+x)的最大值
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 x+y--- = --- = ---- ----y+Z z+x x+y ,求 z 的值 .求 x+y----
(x+y-z)(x-y+z)=
解方程组;1.x+y+z=26,x-y=1,2x-y+z=18 2.5x+y+z=1,2x-y+2z=1,x+5y-z=