Nice
area=pir^2
the areas are
pir^2+pi(2r)^2
they add to 8pi
8pi=pir^2+pi(2r)^2
undistribute pi
8pi=pi(r^2+(2r)^2)
divide both sides by pi
8=r^2+(2r)^2
expand
8=r^2+4r^2
add
8=5r^2
divide by 5
8/5=r^2
sqrt both sides
√(8/5)=r
double since it is double
2√(8/5) is radius of bigger aka (4√10)/5
radius=(4√10)/5
This is just about substitution!! 9(5)-3(5), 3 • 5 = 15
9 • 5 = 45
so Now you have, 45 - 15 = 30
I think it’d be 536,028 at the end of 10 years of growth. I hope this helped.