Respostas

2014-02-04T15:56:19-02:00
100=20 + 8t
-8t= 20 - 100
(-1)-8t= -80(-1)
8t=80
t=80/8
t=10

2014-02-04T16:10:44-02:00
Substituindo, temos
100 m = 20 + 8.t
t = 100 - 20
           8

t = 80/8
t = 10 segundos

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