Acyclist rides his bike at a speed of 18 miles per hour. what is this speed in feet per second? how many feet will the cyclist travel in 15 seconds? in your computations, use the fact that 1 mile is equal to 5280 feet. do not round your answers.

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.