{x+2y+z=8,2x-y-z=-3,3x+y-2z=-1
1个回答

{x+2y+z=8 (1)

{2x-y-z=-3 (2)

{3x+y-2z=-1 (3)

(1)+(2)

3x+y=5 (4)

(1)*2+(3)

5x+5y=15

x+y=3 (5)

(4)-(5)

2x=2

x=1

代入(5)解得

y=2

把x=1、y=2代入(1)得

1+4+z=8

z=3

方程组的解为

{x=1

y=2

z=3