Answer:
r = 
Step-by-step explanation:
A = πr-32
using algebraic manipulation to isolate r
A + 32 = πr-32 + 32
A + 32 = πr
(A+32)/π = πr/π
r = 
Answer:
75%
Step-by-step explanation:

(2.5 x 10^-8)(9 x 10^-10) = (2.5 x 9) x (10^(-8 + (-10))) = 22.5 x
10^(-8 - 10) = 2.25 x 10^1 x 10^-18 = 2.25 x 10^(1 + (-18)) = 2.25 x
10^(1 - 18) = 2.25 x 10^-17
I think it is (5,6). I’m just guessing