12+25\dfrac{1}{2} + \dfrac{2}{5}
12+25\dfrac{1}{2} + \dfrac{2}{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}
25∗22=410\dfrac{2}{5} * \dfrac{2}{2} = \dfrac{4}{10}
Since these fractions have the same denominator, we can just add the numerators
510+410=910\dfrac{5}{10} + \dfrac{4}{10} = \dfrac{9}{10}