∴a、b、c中二负一正,
又b+c=-a,c+a=-b,a+b=-c,
∴
| b+c |
| |a| |
| c+a |
| |b| |
| a+b |
| |c| |
| −a |
| |a| |
| −b |
| |b| |
| −c |
| |c| |
而当a>0时,
| −a |
| |a| |
| −a |
| |a| |
∴
| −a |
| |a| |
| −b |
| |b| |
| −c |
| |c| |
∴
| b+c |
| |a| |
| c+a |
| |b| |
| a+b |
| |c| |
故答案为:1.
| b+c |
| |a| |
| c+a |
| |b| |
| a+b |
| |c| |
| b+c |
| |a| |
| c+a |
| |b| |
| a+b |
| |c| |
| −a |
| |a| |
| −b |
| |b| |
| −c |
| |c| |
| −a |
| |a| |
| −a |
| |a| |
| −a |
| |a| |
| −b |
| |b| |
| −c |
| |c| |
| b+c |
| |a| |
| c+a |
| |b| |
| a+b |
| |c| |