X:y:Z=1:2:7 2X一y+3Z=21 求步子
1.已知x:y:z=4:5:7,求:(一)2x+3y+z/5z; (二)x+y/y+z 非常急,
如果,根号x-3+| y-2 |+z^2=2z-1 求 (x+z)^y
已知x:y:z=4:5:7,求:(1)2x+3y+z/5z; (2)x+y/y+z.
1.x+y+z=21,x-y=1,2x+z-y=13.2.3x+2y+z=13,x+y+2z=7 ,2z+3y-z=12
解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z
已知2x+5y+4z=6 3x+y-7z=-4求x+y-z
已知x:y:z=1:2:3,x+y+z=24,求x,y,z
已知{x:y:z=1:2:3,x+y+z=12,求x、y、z的值
已知x::y:z=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,