Which of the following is equivalent to (81m^6)^1/2

In the surface area formula for cylinders which expressionrepresents the lateral area

Cam bought some used books for $4.95. he paid $0.50 each for some books and $0.35 each for the others. he bought fewer than 8 books at each price. how many books did cam buy?

Combine like terms to make a simpler expression 3z+z