To create a linear equation representing the amount of money Don has paid as a function of months, we need to determine the slope and y-intercept of the line using the information provided.
Let \( x \) be the number of months and \( y \) be the total amount paid.
We have the following two data points:
- After 12 months: \( (12, 5140) \)
- After 36 months: \( (36, 13420) \)
First, we calculate the slope (m) of the line using the formula:
\[ m = \frac{y_2 - y_1}{x_2 - x_1} \]
Where:
- \( (x_1, y_1) = (12, 5140) \)
- \( (x_2, y_2) = (36, 13420) \)
Now substituting the values:
\[ m = \frac{13420 - 5140}{36 - 12} = \frac{8280}{24} = 345 \]
Next, we can use the slope and one of the points to write the equation in point-slope form \( y - y_1 = m(x - x_1) \).
Let's use the point \( (12, 5140) \):
\[ y - 5140 = 345(x - 12) \]
Now, let's simplify the equation:
\[ y - 5140 = 345x - 4140 \]
Adding 5140 to both sides, we get:
\[ y = 345x + 1000 \]
Thus, the linear equation representing the amount of money Don has paid as a function of months is:
\[ y = 345x + 1000 \]