如果x:y:z=3:4:5,且2x+3y-5z=-14,则x y z 为多少,急•﹏•
已知x、y、z满足2x+3y+z=48 x-2y+2z=56 3x+5y+3z=52 则x+y+z的值为多少 急
已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z均不为0,求3x*x+2y*y+5z*z/5x*x+y*y-
如果X:Y:Z=3:4:5,且2X+3Y-5Z=-14,则X= Y= Z=
已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z都不为0,求(3x*x+y*y+4z*z)/(5x*x+y*
200分求数学题,急x+y-z=-14x-3y+2z=162x-2y-3z=5求z等于多少
已知2x+5y+4z=15.7x+y+3z=14 则x+y+z=?
如果x/2=y/7=z/5,x,y,z都不等于0,则(x+y+z)/(3x-y)等于多少?
若x:3=y:4=z:5,且3x-2y+2z=18,则2x+5y-3z=多少
如果x:y:z=3:4:5且2x+3y-5z=-14
已知方程组2x+y-5z=0和3x-3y-z=0.则x:y:z=多少:多少:多少 急
x/2=y/3=z/5 x+3y-z/x-3y+z
1.x+y+z=30,3x+y-z=50,x,y,z为非负数,求5x+4y+2z取值范围.