You add them the same way you do with proper fractions. Make sure they have common denominators and add the numerators.
Example:
\(\frac{3}{2} + \frac{4}{3}\)
\(\frac{3*3}{2*3} + \frac{4*2}{3*2}\)
\(\frac{9}{6} + \frac{8}{6}\)
\(\frac{9+8}{6}\)
\(\frac{17}{6}\)
