Towns A and B are located 6 miles and 3 miles, respectively, from a major expressway. The...

Towns A and B are located 6 miles and 3 miles, respectively, from a major expressway. The point on the expressway closest to town A is 12 miles from the point on the expressway closest to town B. Two new roads are to be built from A to the expressway and then to B

a. Express the combined lengths of the new roads in terms ofx as shown in the figure.

b. If the combined length of the new roads is 15 miles, what distance doesx represent?