3x+1/5y=7 solve for y plz

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

Solve 4 ln x=2ln25 a) x=5 b) x=25 c) x=625

The graph shows the amount of total rainfall at each hour what was the total rainfall amount after three hours