Answer: let x be the number of songs downloaded
Each song is $1.29; the total cost would be found by multiplying the cost by the number of songs or $1.29x.
This cannot be more than 20 so we set this less than or equal to 20
1.29x < 20
To solve this we divide both sides by 1.29
<;
x < 15.5
We cannot download half a song so we round this down to 15 (although the number rounds up mathematically he would not have enough money to download 16 songs.) This means he can download at most 15 songs