Mr. santos is carpeting his living room. the room measures 21 feet by 15 feet. the carpeting costs $9 per square foot. how much carpeting will he need (in square feet), and how much will it cost?

To solve this problem you must apply the proccedure shown below:
 1- You have that the area of the living room is:
 A=lw (Area of the rectangle); where l is the lengt and w is the width.
 A=(21 feet)(15 feet)
 A=315 feet²
 2- The cost is:
 Cost=315 feet²x$9
 Cost=$2835 
 The answer is: He will need 315 feet² and it will cost $2835

Sorry can't answer that question