a+b+c=2 (1)
3a-b-2c=0 (2)
a+2b-c=-3 (3)
(1)+(3)得:
2a+3b=-1;(4)
(1)X2:2a+2b+2c=4;
再与(2)相加得:
5a+b=4(5)
(5)X3得:15a+3b=12
减去(4)得:
13a=13
a=1;代入(5)
b=-1;
c=2;
a+b+c=2 (1)
3a-b-2c=0 (2)
a+2b-c=-3 (3)
(1)+(3)得:
2a+3b=-1;(4)
(1)X2:2a+2b+2c=4;
再与(2)相加得:
5a+b=4(5)
(5)X3得:15a+3b=12
减去(4)得:
13a=13
a=1;代入(5)
b=-1;
c=2;