12+15\dfrac{1}{2} + \dfrac{1}{5}
12+15\dfrac{1}{2} + \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 2 and 5 is 10, so we need to multiply to make each of the denominators = 10
12∗55=510\dfrac{1}{2} * \dfrac{5}{5} = \dfrac{5}{10}
15∗22=210\dfrac{1}{5} * \dfrac{2}{2} = \dfrac{2}{10}
Since these fractions have the same denominator, we can just add the numerators
510+210=710\dfrac{5}{10} + \dfrac{2}{10} = \dfrac{7}{10}