4x+3z=9 2x-6y+4z=5 3x+2y+z=8

2x+5y+4z=6,3x+y-7z=-4,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 解方程组：x+y+z=4,x+y+2z=5,3x+y-z=6 5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z 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. 三元一次方程组2x+z=3 3x+y-z=8 x+3y+2z=3 5x+2y-3z=2 x+2y+z=6 7x-2y-4 解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y 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. 2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai