12/31+18/31

To add the fractions \( \frac{12}{31} \) and \( \frac{18}{31} \), you can simply add the numerators since they have the same denominator:

\[ \frac{12 + 18}{31} = \frac{30}{31} \]

So, \( \frac{12}{31} + \frac{18}{31} = \frac{30}{31} \).