What is the generalised from of 85​

Plzzz i beg u so much asaaaap ! what is the slope of this line? enter your answer in the box.

If 20% of a number is 35, what is 50% of that number?

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