若x,y,z都是正数,且3x+2y-z=4,求x+y+z的取值范围.

若x,y,z都是正数,且3x+2y-z=4,求x+y+z的取值范围. 若x,y,z,满足3x+2y+z=5,2x+y-3z=1.y是非负数.求z的取值范围 1.x+y+z=30,3x+y-z=50,x,y,z为非负数,求5x+4y+2z取值范围. 若x,y,z都是正实数,且x+y+z=xyz,且1/(x+y)+1/(y+z)+1/(z+x)恒成立,求a的取值范围 若2x+y-3z=1,3x+2y+z=5,x、y、z都是非负数,设m=3x+y-7z,求m的取值范围. 已知x,y,z为非负数,且3x+2y+z=5,2x+y-3z=1.若S=3x-y-7z,试求S的取值范围 已知x、y、z是三个非负有理数,且满足3x+2y+z=5,x+2y-z=3,若s=2x+y-z,求s的取值范围 已知x,y,z为3个非负实数,且满足3x+2y+z=5,x+y-z=2,若s=2x+y-z求s的取值范围 已知x,y,z是三个非负有理数,且满足3x+2y+z=5,x+y-z=2,若S=2x-y-z,求s的取值范围 若x:y:z=3:4:5且x+y+z=24,求x、y、z的值 若X:y:Z=3:4:5,且X+Y+Z=24,求X、Y、Z的值 已知x:y:z=2:3:4,且x-y+z=36,求x+y+z的值.