How do you solve the equation (5x/6)(5x/2) = 5^{16}

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 is working backward similar to solving an equation?

Two numbers have a sum of -19. one number is x. what expression represents the other number?