13+15\dfrac{1}{3} + \dfrac{1}{5}
13+15\dfrac{1}{3} + \dfrac{1}{5}
Since these fractions have different denominators, we need to find the least common multiple of the denominators
The least common multiple of 3 and 5 is 15, so we need to multiply to make each of the denominators = 15
13∗55=515\dfrac{1}{3} * \dfrac{5}{5} = \dfrac{5}{15}
15∗33=315\dfrac{1}{5} * \dfrac{3}{3} = \dfrac{3}{15}
Since these fractions have the same denominator, we can just add the numerators
515+315=815\dfrac{5}{15} + \dfrac{3}{15} = \dfrac{8}{15}