1、已知x/y=7/2,求x/x+y 2、已知x/2=y/3=z/4,求x+y+z/2x+3y-z!
已知2x+5y+4z=6 3x+y-7z=-4求x+y-z
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.
已知x/2=y/3=z/4,求下列各式 (1)(x+y+z)/x (2)(x-y+2x/(x-y-2z)
已知3x=4y,2y=5z,试求x:y:z
已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值
已知有理数x、y、z满足条件|x-z-2|+(3x-6y-7)^2+|3y+3z-4|=0,求x、y、z
已知x:y:z=4:5:7,求:(1)2x+3y+z/5z; (2)x+y/y+z.
已知x/3=y/4=z/2,求x+2y-z/x+y+z=?
求下列各连比已知x:y=3:7,y:z=7:5,求x:y:z已知x:y=4:7,y:z=2:5,求x:y:z已知x:y=
已知2x=3y=4z求2x-y+z分之x+y+z的值
已知x:y:z=3:4:5,3x+2y-4z=18.求:x+y+z.
已知x:y:z=2:3:4,且x-y+z=36,求x+y+z的值.