1/7 +3/7

To add the fractions \( \frac{1}{7} + \frac{3}{7} \), you can simply add the numerators since they have the same denominator:

\[ \frac{1 + 3}{7} = \frac{4}{7} \]

So, \( \frac{1}{7} + \frac{3}{7} = \frac{4}{7} \).