If ef bisects zceb, mzcef = (7x + 21)* and mzfeb = (10x - 3), find the measure of zdeb.

Adam drew two same size rectangles and divided them into the same number of equal parts. he shaded 1/3 of one rectangle and 1/4 of the other rectangle. what is the least number of parts into which both rectangles could be divided into?

What number should be added to both sides of the equation to complete this square? x^2-10x=7

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?