x:y=2:3 y:z=4:5 4x-2y+3z=53
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
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-
x/2=y/3=z/5 x+3y-z/x-3y+z
已知3x=4y,2y=5z,试求x:y:z
3x=4y 2y=5z 试求x:y:z
2x+5y+4z=6,3x+y-7z=-4,x+y-z=?
已知x:y:z=3:4:5,3x+2y-4z=18.求:x+y+z.
{2x+3y-4z=-5 x+y+z=6 x-y+3z=10
已知2x+5y+4z=6 3x+y-7z=-4求x+y-z
2x+5y+4z=0,3x+y-7z=0,则x+y-z=?
解方程组:x+y+z=4,x+y+2z=5,3x+y-z=6