Plz i have no clue how to do this i really need

The product of two negative rational numbers is always zero sometimes zero never zero

Elena and her husband marc both drive to work. elena's car has a current mileage (total distance driven) of 15,000 and she drives 23,000 miles more each year. marc's car has a current mileage of 46,000 and he drives 9,000 miles more each year. will the mileages for the two cars ever be equal? explain.

How can you tell when x and y are not directly proportional?