Respuesta :

Answer:

f(a + 1) = 3a + 4

Step-by-step explanation:

Given the function is:

f(x) = 3x + 1

To determine f(a + 1) we have to substitute (a + 1) in place of 'x'.

Therefore, we have:

f(a + 1) = 3(a + 1) + 1

          = 3a + 3 + 1

          = 3a + 4

['a' could be any real number.]

So, f(a + 1) = 3a + 4 is the answer.