What is the rate of change of the line through (2, -7) and (3, 12)

Describe all the numbers that when rounded to the nearest thousand are 645,000

If i have 20$ and i gave 5$ away how much i got

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