4/5 : 3/13

To solve this expression, you need to find a common denominator for both fractions. In this case, the least common multiple of 5 and 13 is 65.

Now, let's convert each fraction to have a denominator of 65.

For the first fraction, multiply both the numerator and denominator by 13: 4/5 * 13/13 = 52/65

For the second fraction, multiply both the numerator and denominator by 5: 3/13 * 5/5 = 15/65

Now that both fractions have the same denominator, you can subtract them: 52/65 - 15/65 = (52 - 15)/65 = 37/65

So, 4/5 - 3/13 = 37/65.