## Elementary Algebra

Sandy leaves a town traveling in her car at a rate of 45 miles per hour. Let t represent the time Sandy travels until she is overtaken by Monica. Since Monica leaves town one hour later than Sandy, the time she travels until she overtakes Sandy is t-1. Because the second car is to overtake the first car, the distances must be equal. So: 45 $\times$ t = 50 $\times$ (t - 1) 45t = 50t - 50 5t = 50 Divide both sides by 5. t = 10 Since Monica overtakes Sandy after t-1 hours, and t = 10, then we know that Monica overtakes Sandy after 10-1 = 9 hours.