Where is the midpoint between -3 and 15 on a number line?

How do i get the answer for 2/3 * 10/3

Solve the equation x/4 - 5= -8 -27 -12 -7 12

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