Length of a rectangular prism volume is 2,830.5, width 18.5, height 9

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?

How do you use the elimination method for this question? explain, because i really want to understand!

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