Respostas

2014-03-25T22:37:46-03:00
5/7 + {3/5 - [9/4 + 10/5 - 1/4] + 2}
5/7 + {3/5 - [45/20 + 40/20 - 5/20] + 2}
5/7 + {3/5 - 80/20 + 2}
5/7 + {12/20 - 80/20 + 40/20}
5/7 - 28/20
100/140 - 196/140
-96/140 = -24/35