Answer:
(1) 14
(2) 3
(3) (4,22)
(4) 24
Explanation:

1) the output of the function when the input g = 2
plug in 2 for g

2) the input for the function when the output is 18
plug in 18 for f(g)

Subtract 6 from both sides

Divide both sides by 4
So g= 3
3) an input and its corresponding output
(4,22) represents g=4 (input) and corresponding output f(4)=22
4) the absolute difference of the input and the output when the input is 6
Plug in g=6

Input is 6 and output is 30, Difference is 30-6 = 24