Question

A social networking site recorded that 80% of the people who became members of the site one month were between 30 and 40 years old. The equation below represents this information, where x represents the total number of people who became members of the site that month:

x = 0.8x + 72

How many people who became members of the site that month were between 30 and 40 years of age?



360

432

112

288