Simplify the expression.

4/5-7/9+1/5

4/5 - 7/9 + 1/5

(4/5 + 1/5) - 7/9

1 - 7/9

9/9 - 7/9

2/9 <==

Find the LCD (Least common denominator) from 5, 9, 5 and that would be 45.

make the denominators the same as the LCD

simplify, now the denominators are equal and in harmony

join the denominators together

simplify and you get 10/45

simplify and your answer would be 2/9.