①3x-4y+z=14x+5y+2z=172x+2y-z=3② x:y=3:2y:z=5:4x+y+z=66

①3x-4y+z=14x+5y+2z=172x+2y-z=3② x:y=3:2y:z=5:4x+y+z=66 x+y+z=6 x+2y+3z=14 y+1=z 3x+2y+z=14 ,x+y+z=10,z+2x+3y=1 5 已知2x+5y+4z=15.7x+y+3z=14 则x+y+z=? x-y+z=-1 5x+2y-z=6 4x-3y+2z=-5 x+y+z=-5,3x+y+z=1,4x+3y+2z=-2快 3x-y+2z=-1 4x+y+z=5 x-2y-z=-2 x+y+z=-1 4x-2y+3z=5 y-z=8-2x x+y+z=1 4x+5y-z=6 x+2y-z=3 {x+y+z=1 {x+3y+7z=2 {x+5y+19z=4 1.{x:y:z=3:4:5 2x+3y-5z=-142.{x-y-z=-1 3x+5y+7z=11 4x-y+2z=-13.{x+y=1 x+z=0 2x+y+2z=44.{x-y+z=-3 2x-y-z=-2 -3x+y+z=-15.{x-y+z=-3 3x+y-4z=6 2x+y-z=36.{x-2y+5z=16 2x+y-5z=7 2x-y+z=38 三元一次方程组,1.x-2y+z=9 2x+y+3z=10 3x+2y1.x-2y+z=92x+y+3z=103x+2y-z2.3x-5y+2z=14x+5y-z=5X-5y+3z=-23.7x+2y-z=76x-y+z=74x+3y+z=94.4x+3y-2z=-75x-6y+z=12x+z=-25.2x+3y-4z=-23x-2y+5z=262x+5z=31 解三元一次方程组 ①2x-y+z=1 3x+y -2z=2 X+2y-z=3 ②x-4y+z=-3 2x+Y-Z=18 X-Y-Z=7 ③4x+4y+2z=7 6X-4y-z=6 2x-y+z=1 x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=? 三元一次方程 X-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 X=?Y=?Z=? 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. x+2y-z=-5 x+y+2z=-1 3x+4y-2z=-12x+2y-z=3 2x+y+3z=0 4x+z=-4 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=?