How do I graph a piece wise function with two equations

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?

What is the value of x when x + 7 = 21?

Ametal rod is 2/5 meters long. it will be cut into pieces that are each 1/30 meters long. how many pieces will be made from the rod?