Melissa of Melissa’s Landscaping Service mows many of the lawns in her neighborhood for $100 per lawn, per month. She also offers full landscape maintenance services for $130 per yard, per month. If Melissa provides full landscaping service for two times the number of yards for which she provides lawn mowing only, and her earnings are $8,280 for a month, for how many yards does Melissa provide the full landscape maintenance service? (25 points)