In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data
Aaron :
fee = $15
rate = $25 per month
Alex:
fee = $40
rate = $20 per month
equation of the line = ?
Step 02:
Equation of the line:
Aaron:
y = 25x + 15
Alex:
y = 20x + 40
The answer is:
Aaron:
y = 25x + 15
Alex:
y = 20x + 40