Answer:
t = 100 - 5n : rule for amount of money left.
You will have $45 left after using downtown parking 11 times.
Explanation:
The equation for an arithmetic sequence in this case is t = a + dn.
a is the initial value, d is the rate of change, and n is the independent variable.
t is the dependent variable.
In this context, a is the starting budget for parking, d is the amount parking costs each time, n is the number of times you use the parking and t is the amount of money left after each time you use the parking.
Substitute the known values from the problem into the equation.
t = a + dn
t = 100 + (-5)n <= the rate of change is -5 because it's decreasing
t = 100 - 5n
To find the amount of money left after 11 times using downtown parking, substitute n for 11.
t = 100 - 5n
t = 100 - 5(11)
t = 100 - 55
t = 45
You will have $45 left after 11 times parking downtown.
