To find out how many miles Wyatt would have run after attending 31 track practices, we can substitute \( p = 31 \) into the equation \( d = p + 19 \).
Substituting \( p \):
\[ d = 31 + 19 \]
Now, we can calculate \( d \):
\[ d = 50 \]
So, after 31 track practices, Wyatt would have run 50 miles.