Please explain to me how to solve:

A circular mirror is surrounded by a square metal frame. The radius of the mirror is 5x. The side length of the metal frame is 15x. What is the area of the metal frame? Write your answer in factored form.

3 answers

area of square = 15x*15x = 225 x^2
area of mirror = pi (25) x^2

area of metal = 225 x^2 - 25 pi x^2

= 25 x^2 (25 -pi)
frame= 15x * 15x = 225x^2

mirror= pi(r)^2 = pi(25x)^2

area of metal(answer in factored form)=225x^2-(25)pi x2 = 25x^2(25-pi)
25x^2(9-pi)