Given problem;
A = 4 π R²
To solve for R, we have to make it the subject of the expression.
Since
A = 4 π R² , follow these steps to find R;
Multiply both sides by
A x
=
x 4 π R²
= R²
Then find the square root of both sides
√R² =
R = 
The solution is 
Answer:
k = 63
Step-by-step explanation:
3 x 21 = 63
Y = 17 is not a linear function.
False. 1/3 of 31 is about 10, so 55 is bigger than 10