Question

x+2y+z=0 x-y+2z=2 2x-y+3z=-1

Answer 1

x+2y+z=0 x-y+2z=2 2x-y+3z=-1

x+2y+z=0 ①

x-y+2z=2 ②

2x-y+3z=-1 ③

①-②得 3y-z=-2 ④

2*①-③得 5y-z=1 ⑤

5*④-3*⑤得 -2z=-13, z=13/2

代入z到④,得y=3/2

代入y和z到①,得x=-19/2

因此 x=-19/2 y=3/2 z=13/2

希望能有帮助,o(∩_∩)o