Find an angle between 0° and 360° that is coterminal with 815°

One month, a music site observed that 60% of the people who downloaded songs from its site downloaded q sam's latest single. the equation below represents this information, where x represents the total number of people who ddownloaded songs from the site that month: x = 0.6x + 384 how many people who downloaded songs from the site that month downloaded q sam's latest single?

Through non-collinear points there is exactly one plane.

Can someone me with the property questions for 12 13 and 14 plz