TEAS ATI Mathematics Practice Test 2026 - Free Essential Academic Skills Practice Questions and Study Guide

The equation y = 15 + 28x effectively models Andy's savings over time, where y represents the total savings, x denotes the number of months that have passed, and $28 indicates the amount saved each month.

In this equation, the term "28x" reflects the total amount saved after x months, as it calculates the monthly savings multiplied by the number of months. The "15" in the equation represents an initial amount that Andy may have had saved before he began saving $28 per month. Thus, the equation accounts for both the existing savings and the ongoing contributions.

The structure of this equation establishes a linear relationship between the time in months and the total savings, which is the appropriate way to represent Andy’s increasing savings over time. Other equations lack either the proper representation of the monthly contributions or do not correctly include any initial savings, failing to accurately model Andy's situation.