Given that n=3+√7,find the value of n-1/n and leave your answer in the form a+b√7

Nash is making a framed enlargement of a mary cassatt postage stamp to present to a retired postmaster. he enlarges the stamp using a scale of 2 inches to 1 centimeter. if the actual length of the stamp is 3 centimeters and its width is 5 centimeters, what are the dimensions of the scale picture? a. the length is 6 inches, and the width is 10 inches. b. the length is 1.5 inches, and the width is 2.5 inches. c. the length is 5 inches, and the width is 10 inches. d. the length is 5 inches, and the width is 7 inches.