Question

解三元一次方程组：{9x-5y+z=5 {9x+y+4z=14 {-9x+3y-5z=-11

Answer 1

9x-5y+z=5 (1)

9x+y+4z=14 (2)

(1)-(2)

2y+z=3

-9x+3y-5z=-11 (3)

(1)+(3)

2y+4z=6

z=1 y=1 x=1