Answer:
Nimer's family paid $489.25 for the car rental
Explanation:
Nimer's family rents an SUV from a company that charges a flat rate of $19.99 plus $0.79 per mile driven.
They travel from St. Louis to Chicago and back. The distance between these cities is 297 miles, so they drive 2*297 = 594 miles.
The total charges include a flat fee of $19.99 and the cost of 594 miles:
$19.99 + $0.79 * 594 = $19.99 + $469.26 = $489.25
Nimer's family paid $489.25 for the car rental