Your record bicycle pace along a favorite trail is 16 mph. on a recent ride, you traveled the 25 mile route in a time of 90 minutes. what was your average speed? did it break your record pace?

Remember that d = rt or distance = rate times time.  You want your answer in miles per hour so convert 90 minutes to 1.5 hours.  Now plug in your values:
25mi = r*1.5hrs.
r = 25/1.5 = 16.667mph.

This is greater than 16mph so you did break your record pace.

The vertex of the quadratic function is (1.5, -.75)