To find the rate of change, we must find the unit rate, or the amount of savings added per month. To find this, we can divide the amount changed from month 4 to month 1 from the amount of months, resulting in (415-160)/3=85 as our rate of change. This means that every month, the amount of money in Brent's savings account adds by 85. Next, the initial value is the starting value, and that is how much money Brent has at month 0. After one month of saving, Brent has 160 dollars. However, he must have added 85 dollars from his starting amount to get 160 dollars after one month of saving. Therefore, 160-85=75 as our starting amount. This means that Brent started with 75 dollars in his account.
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