Need help filling in the blanks

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?

Another type of subtraction equation is 16-b=7. explain how you would sole this equation then solve it.

What is the perimeter of an equilateral triangle if each side is (x+3)?