200分x+y-z=-14x-3y+2x=162x-2y-3z=5 求z值等于多少,
200分求数学题,急x+y-z=-14x-3y+2z=162x-2y-3z=5求z等于多少
X+Y+Z=200,1/3X+4Y+5Z=200,求X,Y,Z等于多少?
已知2x+5y+4z=15,7x+y+3z=14,求4x+y+z等于多少?
已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
x/2=y/3=z/5 x+3y-z/x-3y+z
x/3=y/4=z/5,求x+y+z/3x-2y+z的值,
若x/3=y/4=z/5,求x+y+z/3x-2y+z的值.
x+2y+3z=20,x+3y+5z=31,求x+y+z的值
已知x/4=y/5=z/6 求x+y+z/3x-2y+z的值
已知x/4=y/5=z/6,求x+y+z/3x-2y+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.