Help me please I don’t know how to do these

Assemble the proof by dragging tiles to the statements and reasons column

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 is the area of a triangle with a base of 7x and height of 8x expressed as a monomial? question 5 options: 1x 15x2 28x2 56x2