identify a quadratic function that fits the points (−1, , 4), and (3, 13).
f(x) = 3x^2 − 2x − 4
f(x) = 2x^2 + 3x − 4
f(x) = 2x^2 − 3x + 4

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