Find the sum and difference of the following fractions, reduce answer to lowest term if necessary

1. 3/5 + 2/5 - 1/5 =___

2. 5/15 - 3/15 + 7/15=____

3. 5 - 1 2/3=____

4.3 4/5 + 1 1/4=___

5. From the sum of 9/20 and 5 4/20, subtract 2 11/10=____