Final answer:
An equation that models the balance y after x months for Zachary's computer purchase is:
y = -115x + 1,700
Step-by-step explanation:
The given information provides two data points: at two months ( x = 2 ), the balance is $1,470, and at twelve months (x = 12), the balance is $320. Using these points, we can construct a linear equation in slope-intercept form (y = mx + b), where m is the slope and b is the y-intercept.
First, determine the slope (m):
![\[ m = \frac{{\text{{change in }} y}}{{\text{{change in }} x}} = \frac{{320 - 1,470}}{{12 - 2}} = -115 \]](https://img.qammunity.org/2024/formulas/business/high-school/50ho6zaz7i6iriw5jsy0dwzo024nskupvm.png)
Now that we have the slope (m), substitute it and one of the data points (let's use x = 2, y = 1,470) into the slope-intercept form:
![\[ 1,470 = -115 * 2 + b \]](https://img.qammunity.org/2024/formulas/business/high-school/56na906n6d1s4480fdlr391xe8xnsw16zd.png)
Solving for b:
b = 1,700
Thus, the equation that models the balance y after x months is y = -115x + 1,700. This equation allows us to predict the remaining balance (y) after any given number of months (x).