F (x) = x (to the second power) + 3; g (x) = x - 7.

Which expression is equal to (f + g) (x) ?

A. x (to the second power) - 4

B. x (to the second power) - 14x + 52

C. x (to the second power) + x - 4

D. x (to the third power) - 7x (to the second power) + 3x - 21

Given is function f (x) = x² + 3, and function g (x) = x - 7.

It says to perform the addition operation on functions such that (f+g) (x).

We can simply add the functions as follows : -

(f+g) (x) = f (x) + g (x)

(f+g) (x) = (x² + 3) + (x - 7)

(f+g) (x) = x² + 3 + x - 7

Arranging terms in decreasing order of their degree;

(f+g) (x) = x² + x + 3 - 7

Combining like terms;

(f+g) (x) = x² + x - 4

Hence, option C is correct i. e. (x² + x - 4).