\( \definecolor{colordef}{RGB}{249,49,84} \definecolor{colorprop}{RGB}{18,102,241} \)
A car rental company charges a fixed distance of \( 50 \) km included in the rental and \( 15 \) km for each extra hour of rental.
Find the total distance \( D \) the car can travel in terms of the rental time \( x \) (in hours).
\( D = \)