Help me simplify the following expression, show steps please

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

What are two numbers that have a sum of 15?

Azul has 4 green picks and no orange picks. you add orange picks so that there are 2 orange picks for every 1 green pick. how many picks are there now.