A scuba diver descends farther down into the ocean from an initial depth of 13.6 feet below sea level. The scuba diver descends at a constant rate for 2 1/2 minutes and reaches a depth no more than 48.2 feet below sea level. What is the maximum rate, r, that the scuba diver may descend?

r ≥ 24.72
r ≤ 24.72
r ≤ 13.84
r ≥13.84

What's the denominator

So the first thing we do is to multiply the top equation by 3. the reason i want to do this is i notice there will be a 6y on both equations and can possibly add/subtract them. so we get 6y = -3x + 27. adding that and the second equation we get 6x = 27-15 which is 12. divide by 6 and we get 2. ∴ x = 2. substituting 2 into the first equation we get 2y = -2 + 9 which is 7. divide by 2 and we get 7/2. ∴ y = 7/2, x = 2.