设x/3=y/5=z/7,则x+y/y=? y+3x/3y-2z=?

设x/3=y/5=z/7,则x+y/y=———,y+3z/3y-2z=———. 设3分之X=5分之Y=7分之Z 则Y分之X+Y= 3y-2z分之y+3z= 设3/x=5/y=7/z,则3y-2z/y+3z=什么? 设x/3=y/5=z/7,则x+y/y=? y+3x/3y-2z=? 设|x|-|y|+|z|=|x+y+z|,且|x+y|=4,|y+z|=5,|y|=3,求(x-y-z)^2的值 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z 设z≠0 x、y、z 满足4x-7y-5z=0 2x-y-z=0 求x：y 设z≠0,x、y、z满足4x-7y-5z=0、2x-y-z=0,求x:y 设x,y,z为正数,且xyz(x+y+z)=4,则(x+y)(y+z)的最小值 设z=x/(x+y),求二阶偏导 若3x+7y+z=5,4x+10y+z=3,则x+y+z=? 已知关于x y z的方程组2x-3y+5z=7 x+2y-3z=8,则4x+y-z= 设实数x,y,z满足2x^2+y^+5z^2=3,则x+2y+3z有最 值是 . C语言：int x=5,y=7,z; z=x>y?5>3?++x+y:x:++x-y++ 则z的值为________. 设Z=X+Y,其中X,Y满足X+2Y>=0,X-Y 设f(x+y,x-y)=xy,z=(xy,x/y),则dz= 若x+y+z=3y=2z,则x/x+y+z=? x/2=y/3=z/5 x+3y-z/x-3y+z