Basic fee for parking is $2 + $1 per half hour parked
If the fee $1 for half and hour, this means they'll fee $2 for parking one hour.
Let x be the number of hours, the total cost for parking in the irport will be:
C=2+2x
C repreents the total cost.
Now replace x=72 in the expresion:
C=2+2*72= $146
The total charge for 72 hours parking is $146
