(side note: your formula C = 2πr^2 is incorrect, it should be C = 2πr)
Answer:
r = 9
Step-by-step explanation:
First let's find the circumference of Circle A. To use the formula we need radius. Since we have a diameter just divide by 2 to get radius. 27 / 2 = 13.5
Now plug that into C = 2πr: 2π*(13.5) = 27π
The question says that the area of circle B is 3x this value, so Circle B's area must be: 27π * 3 = 81π
Now plug that into A = πr^2 and solve for r:

(edited to correct a brain fart)
Answer:
Random
Step-by-step explanation:
Answer with Step-by-step explanation:
f(1) = 160 and f(n + 1) = –2f(n)
⇒ f(2)= -2×f(1)
= -2×160
= -320
⇒ f(3)= -2×f(2)
= -2×(-320)
= 640
⇒ f(4)= -2×f(3)
= -2×640
= -1280
Hence, Value of f(4) is:
- 1280