Please help! I don’t understand it my teacher wasn’t here..

What is the value of x in the equation 2(x-4) = 4(2x + 1)?

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

Which number line correctly shows 0.8 + 0.3?