2x+y+4z=17 4x-y-z=-4 2x+y-2z=11
问题描述：
2x+y+4z=17 4x-y-z=-4 2x+y-2z=11
解这个三元一次方程
答
2x+y+4z=174x-y-z=-4 2x+y-2z=11 加起来得 6x-3z = 72x+y+4z=174x-y-z=-4 加起来得 6x+3z = 1312x = 20 x = 20 /12 = 5 / 33z = 13 - 10 =3 z =1 y = 20/3 -1 +4 = 29/3 x y z分别为 5/3 29/3 1