Respostas

2013-08-09T21:17:21-03:00
3/5 - 6 /4 = 12/20 - 30/20 = -18/20

6/8 - 2/8 = 4/8

21/7 - 41/5 = 105/35 - 287/35 = -182/35 
2013-08-09T22:28:43-03:00
3/5 - 6/4 = 12/20 - 30/20 = -18/20 > simplificando > -9/10.

6/8 - 2/8 = 4/8 > simplificando > 1/2.

21/7 - 41/5 = 105/35 - 287/35 = -182/35
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