Given:
Charlie bought a new computer for $450 with his credit card.
He plans to pay the minimum payment of $25 per month.
To find:
The rate of change.
Solution:
Let y be the remaining amount of loan after x months.
Initial amount of loan = $450
Payment of one month = $25
Payment of x months = $25x
Now,
Remining amount = Initial amount of loan - Payment of x months
...(i)
The slope intercept form is
...(ii)
where, m is slope and b is y-intercept.
From (i) and (ii), we get
Therefore, the rate of change is -25 dollars.