Respuesta :

Evaluating an equation

In order to find f(6) we just need to replace x = 6 in all x of the equation:

f(x) = x - (-x)

f(6) = 6 - (-6)

since - (-6) = 6, then

f(6) = 6 - (-6)

= 6 + 6

Therefore, f(6) = 12

Answer: C. 12