Hey can you me posted picture of question : )

Which one ? is the answer and how to find this answer

Simplify. (-2)^-3 a. -8 b. -1/8 c. 1/8 d. 8

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