Question

Perform the indicated operation

g(a) = 3a + 1

f(a) = a3 + 2

Find g(a) + f(a)

Answer 1

just add the two functions.
g(a)+f(a)=3a+1+3a+2=6a+3

Answer 2

HOW

Answer 3

You can substitute g(a) for 3a+1 and f(a)for 3a+2.
So the sum of g(a)+f(a) is equivalent to the sum of their substitutions.
its like x=6 and y=7, x+y=6+7=13