Given the following functions f(x) and g(x), solve (f + g)(3) and select the correct answer below:

f(x) = 2x + 21

g(x) = x − 24

a)−27
b)−21
c)6
d)48
i think its d but im not sure me im right? ,

You can evaluate the functions separately, then add results:
.. f(3) = 2*3 +21 = 27
.. g(3) = 3 -24 = -21
(f +g)(3) = f(3) +g(3) = 27 -21 = 6

Or, you can find the combined function and evaluate that for x=3.
.. (f +g)(x) = f(x) +g(x)
.. = (2x +21) +(x -24)
.. = 3x -3
The
.. (f +g)(3) = 3*3 -3 = 6

Either way, the best choice is C) 6.

Iam thinking the answer is a.) knew