9. a cylinder with height 15 has a total surface area that is twice the
area of a circle whose radius is 6 more than the radius of the
cylinder. what is the radius of the cylinder?

Find the greatest common factor of -30x 4 yz 3 and 75x 4 z 2.

Jonathan can type 20 documents in 40 minutes ,and susan can type it in 30 minutes and jack can type it in 24 minutes working together ,how much time will it is take them type the same document

Two friends are reading books. jimmy reads a book with 21,356 words. his friend bob reads a book with one-and-a-half times as many words. which expression represents the number of words bob reads?