Plz do all of it plz i will give brailest and thanks to best answer.

The parabola x = y² - 9 opens: a.)up b.)down c.) right d.)left

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

Varies inversely with x. if y=8.5 when x=-1 find x when y=-1