a+b+c=2 (1)
2a-b+3c=-1 (2)
3a+b+2c=1(3)
(1)式+(2)式:
3a+4c=1 (4)
(2)式+(3)式:
5a+5c=0 (5)
(4)式×5-(5)式×3:
5c=5,
c=1
代入(5)解得:a=-1
把a、c的值代攻(1)解得:b=2
a+b+c=2 (1)
2a-b+3c=-1 (2)
3a+b+2c=1(3)
(1)式+(2)式:
3a+4c=1 (4)
(2)式+(3)式:
5a+5c=0 (5)
(4)式×5-(5)式×3:
5c=5,
c=1
代入(5)解得:a=-1
把a、c的值代攻(1)解得:b=2