Finding functions plz help math

Question

Consider the following functions. f(x)=5x+7 and g(x)=x+3

1)  Find (f+g)(x)

2)  Find (f+g)(3)

Answer 1

(f + g)(x) just means to add f(x) and g(x) together, that is (f+g)(x) = f(x) + g(x)

(f + g)(3) means f(3) + g(3).

f(3) is the value of f(x) when x = 3 and g(3) is the value of g(x) when x = 3.