题干
已知a，b，c是不为0的实数，且
=
,
=
,
=
，那么
的值是____ ．
| a |
| b |
| a |
| + |
| b |
| 1 |
| 3 |
| b |
| c |
| b |
| + |
| c |
| 1 |
| 4 |
| c |
| a |
| c |
| + |
| a |
| 1 |
| 5 |
| a |
| b |
| c |
| a |
| b |
| + |
| b |
| c |
| + |
| c |
| a |
答案(点此获取答案解析）
| 1 |
| 6 |
若
，
，则