To add these fractions, we need to find a common denominator. The least common multiple of 5, 4, and 4 is 20.

Converting each fraction to have a denominator of 20:

4/5 = (4/5) * (4/4) = 16/20
3/4 = (3/4) * (5/5) = 15/20
1/5 1/4 = (1/5) * (4/4) + (1/4) * (5/5) = 4/20 + 5/20 = 9/20

Now, we can add the fractions:

16/20 + 15/20 + 9/20 = (16 + 15 + 9)/20 = 40/20 = 2

Therefore, 4/5 + 3/4 + 1/5 1/4 = 2.