To describe the relationship between the number of hours driven \( h \) and the total amount of miles driven \( m \), we can use the following linear equation:
\[ m = 65h \]
This equation states that the total miles driven \( m \) is equal to the speed (65 miles per hour) multiplied by the number of hours driven \( h \).
Now, to find out how far they drove after 7 hours, we can substitute \( h \) with 7 in the equation:
\[ m = 65 \times 7 \]
Calculating that:
\[ m = 455 \]
So, after 7 hours, they drove 455 miles.