writing equations in slope point

Question

You want to order posers to advertise your band. A company charges $109.95 for the first 100 posters and $65 for each additional 100 posters.

Write an equation that represents the cost (in dollars) of the posters of the number (in hundreds) of posters ordered (in slope- intercept form).

Answer 1

Start with the point=slope form: 65=(y-109.95)/(x-100).

Now algebraically re-arrange this to the slope-intercept form.