Given f(x) = 3x + 4 and g(x) = 8x + 1
then what is ( f + g )(

     •   f(x) = 3x + 4

     •   g(x) = 8x + 1

Sum both functions above:

     (f + g)(x) = f(x) + g(x)

     (f + g)(x) = (3x + 4) + (8x + 1)

     (f + g)(x) = 3x + 8x + 4 + 1

     (f + g)(x) = 11x + 5

Therefore,

     (f + g)(0) = 11 · 0 + 5

     (f + g)(0) = 0 + 5

     (f + g)(0) = 5   <———   this is the answer.

I hope this helps! =)