This nal project discusses a three of unit fraction 1 x ; 1 y ; 1 z that satises the sum of fractions a b = 1 x+1 y +1 z ; 0 < a < b; 0 < x ≤ y ≤ z. From this sum of fractions it is obtained a form of the denominators solution for x; y; z with application the form of quadratic equations. In general, another fraction a b can be described as the sum of three unit fractions 1 x …