Respuesta :

Answer:

f(3n) = 27n^2 - 7

Step-by-step explanation:

f(3n)....means that we substitute x for 3n...;

;3(3n)^2 - 7

;3(9n^2) - 7

; 27n^2 - 7

Hence giving you

f(3n) = 27n^2 - 7