yacotabaiwalu
Aug 4, 2010, 03:36 PM
it cost pacific printing $23 to print 200 business cards and $35 to print 500 business cards. Let y be the cost of printing x cards. Question? What is the cost function if it is linear?
Unknown008
Aug 5, 2010, 01:54 AM
If you let y = cost of printing and x = number of cards, then you can say that you have two points (x, y).
So, you get:
(200, 23) and (500, 35)
You have two points, find the equation of the line passing through both points, having the form: y = mx + c where m is the gradient.
The way I do this is finding the gradient first using \frac{y_2-y_1}{x_2-x_1} = m
Then, I use the gradient with one point (either one) and make y the subject of formula:
\frac{y - (y-coordinate)}{x - (x-coordinate)} = m
Post what you get :)