I don’t really know how to do this, could anyone help? :)

What is the point-slope equation of a line with slope -5 that contains the point (6,3)

Suppose you are an avid reader and are looking to save money on the cost of books instead of paying about $20 for each book, you decide to look into purchasing a kindle for $120 you can purchase e-books for about $5 each 1. find the slope-intercept equation for the cost of the hard copy of books using x to represent the number of books 2. find the slope-intercept equation for the cost of the kindle with cost of e-books using x to represent the number of books

Kayaks rent for $35 per day. which expression can you use to find the cost in dollars of renting 3 kayaks for a day?