To begin you need to convert the fractions into something they both can go into. Sometimes it is easier to multiple the two denominator of the fractions, which in this case it is. So, 3 times 5 is 15 This means your going to convert your fraction into 15th
1/3 is 5/15 This is because you need to times the bottom by 5 in order to get 15, so you need to do the same with the top.
1/5 is 3/15 This is because you need to times the bottom by 3 to get 15 so you do the same with the top
Next you just subtract the amounts separately 4-2 = 2 5/15 - 3/15 = 2/15
