Question

Sejam f(x) = 3x e g(x) = 5x +1 , determine:
a) f(g(x))
b) g(g(x))

Answer 1

Resposta:

a)

$g(x) = 5x + 1 \\f (g(x)) = 3x = 3(5x + 1) = 15x + 3 \\ \\ 15x + 3 = 0 \\ 15x = - 3 \\ x = - \frac{3}{15} \\ x = - \frac{1}{5}$

b)

$g(g(x)) = 5x + 1 = 5(5x +1 ) + 1 = 25x + 5 + 1 = 25x + 6 \\ \\ 25x + 6 = 0 \\ 25x = - 6 \\ x = - \frac{6}{25}$