Greatest common factor of 7x² and 21x

21 a stick 7 inches long is broken into two pieces, so that one piece is twice as long as the other one. how long are the two pieces?

There are 93 calories in a small candy bar how many calories are ther in a half dozen small candy bars?

Zach spent 2/3 hour reading on friday a 11/3 hlurs reading on saturday. how much more time did he read on saturday tha on friday