4x-9z=171.{3x+y+15z=18x+2y+3z=22x+4y+3z=92.{3x-2y+5z=115x-6y+7z=13

2x+3y-z=9,x+y+z=15,5x-4y-z=0 2x+3y+z=13 4x^2+9y^2+z^2-2x+15y+3z=82 求x,y,z 4x-9z=17 3x+y+15z=18 x+2y+3z=24x-9z=17 3x+y+15z=18 x+2y+3z=2方程组 4X-9Z=17 3X+Y+15Z=18 X+2Y+3Z=2 4x-9z=17 3x+y+15z=18 x+2y+3z=2 ｛4x-9z=17 3x+y+15z=18 x+2y+3z=2 {4x-9z=17{3x+y+15z=18{x+2y+3z=2 4x-9z=17 3x+y+15z=18 x+2y+3z=2x+y+z=26 x-y=1 2x+z-y=18 x+y/2=z+x/3=y+z/4 x+y+z=27 x+2y=3x+2z=4y+z 求x:y:z x,y,z不是0.3z=4y,z=3x求（x+y）：（x+z）. 方程组2x+3y-z=9 x+y+z=15 5方程组2x+3y-z=9 x+y+z=15 5x-4y-z=0的解, 三元一次方程x+y+z=0 4x+2y+z=3 9x+3y+z=6x+y+z=04x+2y+z=3 9x+3y+z=6 解方程 x+y+z=0 4x+2y+z=3 9x-3y+z=28解方程x+y+z=04x+2y+z=39x-3y+z=28 x+y=5 2x+3y-z=9 x-y+z=4 方程组3x-y-z=9,2x+y-2z=6,x+y+z=15 x+2y+3z=10,4x+3y+2z=15则x+y+z= x+2y+3Z=10,4x+3y+2z=15,求x+y+z=