已知x:y=0.5:0.3,y:z=15:12
x+y+z=14,x'+y'+z'=15,(x-x')+(y+y')+z*z'=16,已知xyz为自然数,求x,y,z的
已知20(x+2y)=15(y+3Z)=12(z+5x),则x:y
已知X+Y=12 Y+Z=10 求X Y Z各等于几
已知x+y-z/z=x-y+z/y=-x+y+z/x,且xyz不等于0,求分式[(x+y)(x+z)(y+z)]/xyz
已知:(x+y-z)/z=(x-y+z)/y+(y+z-x)/x,且xyz≠0,求代数式[(x+y)(y+z)(x+z)
已知{x:y:z=1:2:3,x+y+z=12,求x、y、z的值
已知x,y,z满足方程组x+2y-z=21 x-y+2z=12
已知(x+y-5)平方+(z-x-12)平方+(y-z-15)平方=0,那么x+y+z=多少?
已知x-y+z=0.3x+y-5z=0,则x+y+z/x+2y-3z=_______
已知 x/(y+z)+y/(z+x)+z/(x+y)=1
已知x+y/2=y+z/3=z+x/4,且x+2y+z=12,求x-2y+z的值
已知x+y/2=y+z/2=x+z/4,且x+2y+z=12,求x-2y+z