若|x-3|+|y+4|+z-5|=0,求代数式x+y-z的值
已知x-4y=0,z=5x(x不等于0),求代数式x-14y+3z/x+y+z的值
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
若x:y:z=2:5:7求代数式3x+4y-2x/2x+2y+z的值
若x-y=6,xy=-8,求代数式(x+y+z)²+(x-y-z)(x-y+z)-2·z(x+y)的值
若x/3=y/4=z/5,求x+y+z/3x-2y+z的值.
若x/2=y/3=z/4不等于0,求x+y+z/x+y-z的值
若x:y:z=3:4:5=6,求x-y+z分之x+y-z的值
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=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
问道数学题:已知x/4=y/5=z/6,求代数式2x+3y+4z/5x-3y-4z的值.
已知x/4=y/5=z/6,求代数式(2x+3y+4z)/(5x-3y-4z)的值