Gloria deposited $500 into a bank account that earned 7.5% simple interest each year. she earned $225 in interest before closing the account.
if no money was deposited into or withdrawn from the account, for how many years was the money in the account?
round your answer to the nearest whole year.

Simple interest is money you can earn by initially investing some money (the principal). It can be calculated by the equation expressed as:

I = Prt

where P is the Principal amount of money to be invested at an Interest Rate R% per period for t Number of Time Periods.

We calculate as follows:

225 = 500(.075)t
t = 6 years 

Y=-2x-6 is the answer