<h2>Equations of Circles</h2>
Generally, you'd see the equation of a circle organized in the following format:

is the center
is the radius
To determine the equation given the center and the radius:
- Plug both pieces of information into the general equation
- Simplify
<h2>Solving the Question</h2>
We're given:
- Radius: 99
- Center: (-1,-8)
Plug the radius and center into the equation as r and (h,k):

<h2>Answer</h2>

Answer:
1) 8.5x10^8
2) 5.3x10^-3
3) 9.95x10^12
Step-by-step explanation:
Since they have the same exponents, you just add or subtract and leave the rest the same.
1) 8.5x10^8
2) 5.3x10^-3
3) 9.95x10^12
2040 = n/2(20+(n-1)4)
4080 = n(20+4n-4)
4080= 20n +4n^2 -4n
1020 = 4n + n^2
n^2 +4n -1020 =0
use common formula (can't write out so just look at answers. sorry)
which gives answers of n=-34 and n=30. since n can only be positive, n=30 so there are 30 rows. I liked that challenge