Convert x=9 from rectangular to polar form

Which of the following expressions is equal to 2x^2+8

Bob is putting books on a shelf and takes a break after filling 18 1/2 inches on the book shelf. the book shelf is now 2/3 full. how long is the entire bookshelf?

Find the measure of angle y. round your answer to the nearest hundredth. ( type the numerical answer only) a right triangle is shown with one leg measuring 5 and another leg measuring 14. an angle across from the leg measuring 5 is marked y degrees. numerical answers expected!