Answer:
- <em>convert </em>the mixed fractions to improper fractions (where the numerator is greater than or equal to the denominator): multiply the whole number part by the fraction's denominator, add that to the numerator, write the result on top of the denominator.
- if the denominators are not the same, work out the common denominator and <em>rewrite </em>the fractions with the same denominators
- subtract by subtracting the numerators and writing the result over the denominator
- convert back to mixed fractions by dividing the numerator by the denominator, write down the whole number answer, write down the remainder above the denominator.
Example

convert to improper fractions:

common denominator = 3 × 5 = 15, so:

subtract:

convert back to mixed fractions:

Given statement is "You download 12 new songs to your MP3 player. then you delete 5 old songs."
We have to write each amount as an integer.
Download 12 new songs means you are adding number to your MP3 player so we will use + sign for 12
So the amount in integer form will be +12
Ddelete 5 old songs means you are subtracting number from your MP3 player so we will use - sign for 5
So the amount in integer form will be -5
combining both expressions we can write final statement as:
+12-5
Which can be simplified to +7.