Question 2608
Let the radius of the smalled dartboard be t
Then the area of the dartboard will be pi*t^2
as the area of the circle is pi*r^2

Radius of the bigger dartboard will be (t+3)
so area will be pi*(t+3)^2

Difference in area of two dartbaords will be
pi*(t+3)^2 - pi*t^2
=> pi(t^2 + 6t + 9 -t^2)
=> pi(6t+9)
=> 3pi(2t+3)