Helen purchased 3 copies of a book online at a 20% discount. she paid $10 for shipping that was not discounted. write an equation that represents the cost of buying a book online. how much was the original price of one copy of the book if her total ended up being $40?

(05.03 mc) part a: explain why the x-coordinates of the points where the graphs of the equations y = 4x and y = 2x−2 intersect are the solutions of the equation 4x = 2x−2. (4 points) part b: make tables to find the solution to 4x = 2x−2. take the integer values of x between −3 and 3. (4 points) part c: how can you solve the equation 4x = 2x−2 graphically? (2 points)