[tex] \frac{5}{8} + \frac{9}{8}[/tex] simplified is [tex] \frac{5+9}{8} [/tex]
you do the addition first which results to:
[tex] \frac{14}{8} [/tex]m
and if you need to change it to mixed fraction the result is:
[tex]1 \frac{6}{8} [/tex]m (simplify)≈[tex]1 \frac{3}{4} [/tex]m