Respuesta :

f(x) = x + x

     = 2x

Since there are no restrictions on "x", then the domain is ALL REAL NUMBERS

(-∞, ∞)

g(x) = x + 8x + 2

      = 9x + 2

Since there are no restrictions on "x", then the domain is ALL REAL NUMBERS

(-∞, ∞)

Answers: domain f(x) = (-∞, ∞), domain g(x) = (-∞, ∞)