Respostas

2014-07-23T14:45:09-03:00
Olá, Betinaalves!

a)
V = 13 - 2t
V = 13 - 2 . 13,5
V = 13 - 27
V = -14 km/h

b)
0 = 13 - 2t
-13 = -2t . (-1)
13 = 2t
2t = 13
t = 13 / 2
t = 6,5