## Thinking Mathematically (6th Edition)

$\dfrac{7}{10}$
The fractions are not similar since they have different fractions. Make the fractions similar using their LCD of $10$. $\dfrac{1}{2} + \dfrac{1}{5} \\=\dfrac{1\color{blue}{(5)}}{2\color{blue}{(5)}}+\dfrac{1\color{blue}{(2)}}{5\color{blue}{(2)}} \\=\dfrac{5}{10}+\dfrac{2}{10}$ Now that the fractions are similar, add the numerators and copy the denominator to obtain: $=\dfrac{5+2}{10} \\=\dfrac{7}{10}$