Respostas

2014-08-19T19:56:57-03:00
O numero é 17
17x2= 34+15= 49
2014-08-19T20:09:23-03:00
2 x + 15 = 49
2 x = 49 - 15
2 x = 34
x = 34/2
x = 17

Tirando a prova

2 x 17 + 15=
34 + 15 = 49