Answer:
The final integration in the given limits will be 89.876
To set the equation,we can first find how much price would be raised within a year:
=500×(1+7%)
=500×1.07
As the years go by the increase would accumulate,and the equation would be:

Hope it helps!
10P4 = 10! / (10-4)! = 10*9*8*7 = 5040
9C4 = 9! / 5! 4! = 9*8*7*6 / 4*3*2*1 = 126