To represent the number of hours \( h \) that Tyrell still needs to volunteer to reach his goal of 26 hours, we can set up the equation:
\[ h + 17 = 26 \]
Now, to solve for \( h \), we subtract 17 from both sides of the equation:
\[ h = 26 - 17 \]
Calculating the right side gives us:
\[ h = 9 \]
So, Tyrell still needs to volunteer 9 hours to reach his goal for this month.
In summary:
\[ h + 17 = 26 \]
\[ h = 9 \]