{7x+3y-5z=8 y:x:z=5:3:8

{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 2x+3y-z=11 2x+y-5z=8 -2+7y+z=19 2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X 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 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai {7x+3y-5z=8 y:x:z=5:3:8 若x+3y+5z=10,5x+z+3y=8,x+y+z=? 已知方程组3x+5y+3z=0,3x-5y-8z=0,并且z≠0,求x:z和y:z （1）3x+4z=7;2x+3y+z=9;5x-9y+7z=8 (2)3x+4y+z=14;x+5y+2z=17;2x+ x/2=y/3=z/5 x+3y-z/x-3y+z x/10 = y/8 =z/9 求x+2y+3z/y-5z 三元一次方程组：1、3x+4z=7 2x+3y+z=9 5x-9y+7z=8 2、2x+4y=3z 3x-2y+5z 5