What is the value of y in 3y + 9 = 45

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

X+y=-4 x-y=2 use elimination with adding and subtraction

You buy a veido game for $60 and the sales tax is 8% what is the total cost for the game including the sales tax