Respuesta :

f(2) = 3(2)^2 + 2(2) + 4

= 3(4) + 4 + 4

= 12 + 8

f(2) = 20

f(a+h) = 3(a+h)^2 + 2(a+h) + 4

= 3(a^2 + 2ah + h^2) + 2a + 2h + 4

f(a+h) = 3a^2 + 6ah + 3h^2 + 2a + 2h + 4