Answer :
From the question, you can get an equation
9.99 + 0.25x = 113.74
subtract 9.99 from both sides
and get 0.25x = 103.75
then divide both sides by 0.25
so x = 103.75/0.25 = 415
so the number of songs you downloaded is 415
9.99 + 0.25x = 113.74
subtract 9.99 from both sides
and get 0.25x = 103.75
then divide both sides by 0.25
so x = 103.75/0.25 = 415
so the number of songs you downloaded is 415
(113.74-9.99)/.25 Is a pretty simple means to achieving the answer, which is 415 songs.