Respostas

2013-11-14T15:55:00-02:00
(5.2-4.+7)-(3.2+7.-1)
(10-28) - (6-7)
-18-1
-19
2013-11-14T16:00:26-02:00
( 10 - 28 ) - ( 6 -7 ) =
( -18) - ( - 1 ) =
- 18 + 1 = - 17