Please help me with this question!! TRIGONOMETRY

Find dy/dx using implicit differentiation ln(20+e^xy)=y

Describe the relationship between the angles of similar triangles and the sides of similar triangles

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