Math word problem

Question

a washer is made by removing a circular disk from the center of another circular disk of radius 11 mi. If the disk that is removed has radius x, write a completely factored polynomial whose values give the area of the washer

Answer 1

Area of washer = π(outer radius)² - π(inner radius)²

 

                      = π(11)² - πx²

 

                      = π(11² - x²) = π(11 - x)(11 + x)