What category does the number 5 go under

The area of a rectangle is 15+5y square feet. which of the following expressions could be the length of the sides of the rectangle, in feet a. 5 and 3y b. 5 and 3+y c. 5 and 5+y d. 3 and 5+3y

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

The perimeter of a rectangular rug is 24 feet. the length of the rug is 1 2/5 i s width. what is the area of the rug