The Yert family hires a landscaping company for 30 weeks. There are two companies to choose from. Green Lawns charges for the first time they service your lawn, and the price will multiply by a factor of every week thereafter. Green Thumbs charges for the first time they service your lawn, and then charges an additional every week thereafter. At 30 weeks, if the Yert family chooses the company that is cheaper, how much money will they save?