I need help for this equation.

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

Someone answer this asap for gabriella uses the current exchange rate to write the function, h(x), where x is the number of u. s. dollars and h(x) is the number of euros, the european union currency. she checks the rate and finds that h(100) = 7.5. which statement best describes what h(100) = 75 signifies? a. gabriella averages 7.5 u. s. dollars for every 100 euros. b. gabriella averages 100 u. s. dollars for every 25 euros. c. gabriella can exchange 75 u. s. dollars for 100 euros. d. gabriella can exchange 100 u. s. dollars for 75 euros.

Triangles abc and dfg are given. find the lengths of all other sides of these triangles if: b ∠a≅∠d, ab·dg=ac·df, ac=7 cm, bc=15 cm, fg=20 cm, and df-ab=3 cm.