4 is again c because you should put the 2 here 2a'2-1 so this is 2a'1 and this is 20 so
A2 is 20
Than you should again do this and find a3 ...
The correct answer would be A! (:
What you need to do is add the two equations and combine like terms to get h(x). Refer to the photo for a better explanation.