Question

已知a,b,c为角ABC的三边.化简|a+b-c|+|b-c-a|-|c-a-b|

Answer 1

|a+b-c|=a+b-c

|b-c-a|=c+a-b

|c-a-b|=a+b-c

|a+b-c|+|b-c-a|-|c-a-b|

=(a+b-c)+(c+a-b)-(a+b-c)

=a+b-c+c+a-b-a-b+c

=a-b+c