Need help on this ight

How many $20 bills do you need to have to make $280

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

In terms of x, find an expression that represents the area of the shaded region. the outer square has side lengths of (x+5) and the inner square has side lengths of (x-2), as shown. area: a1 x + a2 square units submit