X+2Y+3Z=18 X+4Y+3Z=24 Y=?

试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, 解方程组x-4y+z=-3,2x+y-z=18,x-y-z=7. 已知x:y:z=2:3:4,且x+y+z=18,求x,y,z的值 x/2=y/3=z/5 x+3y-z/x-3y+z 若X.Y.z满足2X+3Y+z=18,4X-3Y+5z=24,求X+3Y的值 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai 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 若x、y、z满足2x+3y+z=18,4x-3y+5y=24,求x+3y的值. 1.x+y=16,y+z=12,z+x=102.3x-y+z=4,2x+3y-z=12,x+y+z=63.x+y+z=6 已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z均不为0,求3x*x+2y*y+5z*z/5x*x+y*y- 已知3x=4y,2y=5z,试求x:y:z