X:Y:Z=5:7:6 ﹛ 20X+10Y+5Z=48000
3x+7y+z=5 ,4x+10y+z=6 ,x+y+z=
若4x-3y-6z=0,x+2y-7z=0,求代数式5x*5x+2y*2y-z*z/2x*2x-3y*3y-10z*10
2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X
若3x+7y+z=5,4x+10y+z=3,则x+y+z=?
2x+5y+4z=6,3x+y-7z=-4,x+y-z=?
{2x+3y-4z=-5 x+y+z=6 x-y+3z=10
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满足3x+7y+z=5 4x+10y+z=3 求x+y+z的值
已知x、y、z满足{3x+7y+z=5 ,求x+y+z的值 {4x+10y+z=3
已知5分之X+Y=6分之Y+Z=7分之x+z,且X,Y,Z都不等于0,求X:Y:Z的值
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2