Amelia is starting a new exercise routine. On the first day, she will do 8 sit-ups. On the second day, she will do 12 sit-ups. On the third day, she will do 16 sit-ups. On the fourth day, she will do 20 sit-ups. Write an explicit formula for the sequence of the number of sit-ups Amelia will do.

(1 point)
Responses

an = 3n + 2
a n = 3 n + 2

an = 4n + 4
a n = 4 n + 4

an = 6n – 4
a n = 6 n – 4

an = 10n – 2