Hi!
First, let's find the LCD of the denominators. (5, 4, and 2)
2, 4, 6, 8, 10, 12, 14, 16, 18, 20
4, 8, 12, 16, 20
5, 10, 15, 20
Now we have to change all of the numerators to match the denominators.
Since 5 goes into 20 four times..
2 x 4 = 8
8/20
Since 4 goes into 20 five times...
3 x 5 = 15
15/20
Since 2 goes into 20 ten times...
1 x 10 = 10
10/20
Our new fractions are..
8/20+15/20+10/20=?
Now just add the numerators.
33/20
If you want to simplify it to a mixed number, your answer is 1 13/20
If you want to keep it as a fraction, it's already in simplest form. So the answer is 33/20
Hope this helps! :)