Because it goes up for a constant rate, to find the rice for 1 hour of parking do 16.00-12.50 and get 3.50 . To find the fee, just subtract 12.5 - 3.5
The fee for parking is $9
Hope this helps
log 4 ( a^5 ) - log 4 ( b^6 ) =
log 4 ( a^5 / b^6 )
I will try to get back to you a little later