Simplify this eqaution

Question

A circular window is surrounded by a circular frame. The radius of the window is z − 5 and the radius of the full circle formed by the frame is z + 5. Write a polynomial that represents the area of just the frame itself, not including the space covered by the window.
(The area of a circle is given by A = πr 2, where r represents the radius of the circle.

Answer 1

Think hole in the doughnut!

(z + 5)²π - (z - 5)²π

 

Can you simplify and combine?