K/3=39 solve for k. I need it ASAP! I’m in middle school and I suck at math.

Multiply. write your answer in simplest form. 3/8 x 5/7

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

Find two numbers if their sum is 91 and the ratio is 6: 7?