Which function has an inverse that is also a function?

Use the distance formula to determine the distance that point q is from r on the hypotenusebased on a 2-3 ratio.i need asap !

Which of the following expressions are equivalent ?

Problem melissa is her dad build a walkway in their backyard. the walkway will be 54 feet long and 1.5 feet wide. the local hardware store sells tiles which are 1.5 by 1.5 feet and come in boxes of 12. how many boxes of tiles do they need?