Simplify: (4x2 + 21xy – 7y2) + (10x2 + 11y2 – 20).
HELP PLEASEEE

Two rectangular prisms have the same volume. the area of the base of the blue prism is 418 4 1 8 square units. the area of the base of the red prism is one-half that of the blue prism. which statement is true?

50 points~ ! i have to turn this in tomarrow

Sean is his dad build a tiled walkway in their backyard. the walkway will be 6060 feet long and 22 feet wide. the local hardware store sells tiles which are 22 by 22 feet and come in boxes of 66. how many boxes of tiles do they need?