Constant of proportionality of x=9 and y=4

What are different types of statistical programs

Which shows the correct substitution of the values a,b and c from the equation 1=-2x+3x^2+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