It's thirteen because it is too large.
subtract the fee from the total to get the amount actually spent on songs
23.80-7 = 16.80
divide that amount by price per song to get number of songs downloaded
16.80 /0.20 = 84 songs
|-5| is equivalent to 5, since that is how far -5 is from 0.
So, the question is simplified to: How far away is -5 from 5?
We get 5-(-5)=10.
Remember, absolute value is always positive (expect for 0) and the distance between two numbers is always positive (expect for 0).