Respostas

2013-12-26T13:45:38-02:00
 f(f(b)) = 5.(5b+3) + 3 = -2
 f(f(b)) = 25b + 15 + 3 = -2
 f(f(b)) = 25b + 18 = -2
 f(f(b)) = 25b = -2 -18
 f(f(b)) = 25b = -20
 f(f(b)) = b = -20 / 25
 f(f(b)) = b = -4 / 5