Question

Janet's car insurance payment decreases by $30 each year. Which expressions represent the total change in her payment, in dollars, after 4 years?

Answer 1

The change after five years is equal to -$100

Explanation:

If the insurance payment is equal to P = N dollars, where P is a real number, we know that after one year, the payment decreaces by $20, so the new payment is:

P = N - $20

Then, after 5 years, the $20 dollars are discounted five times, so the payment will be:

P = N -5*$20 = N - $100

Then the total change after 5 years is equal to those $100 that are being subtracted in the last equation.