题目

Name: Off the Beaten Path Cover price: $30.00 Our price: $l9.80 The best-selling Reader’s Digest travel book has 40% new content including over 200 new sites, over 200 new full-color photographs, and all-new, up-to-date maps. It spotlights over l, 000 of the United States’ most overlooked must-see destinations. Name: Container Gardens by Number Cover price: $l5.95 Our price: $9.49 A unique book contains 50 easy-to-follow container designs. Each design provides a simple numbered planting plan that shows exactly how to create each display, with an instruction of the finished planter a已知，则的值为_____________．