jawablah dengan benar beserta caranya

diket : f(x) =4x + 7
g(x) = x^2 -1


= f(2x) - g(x + 1)

f (2x) = 4 (2x) + 7
= 8. 4x + 7
4x = 8+7
x = 16/4
x = 4
g(x + 1) = x^2 - 1
= (x + 1)^2 - 1
= (