Complex problem, price per ride = 1.25 + 0.05x ; number of riders = 80,000 - 1000x
Toal income = price per ride times number of riders so (1.25 + 0.05x)(80,000 -1000x)
multiply to get quadratic, put in standard form solve for x coordinate of vertex -b/2a to get
the number of times you should raise rate by 5 cents to yield maximum profit.
I hope this helps