The two numbers that add to make twenty and have a difference of 4 are 12 and 8
So it’s -3 and the second one is +4
<u>Given</u>:
The equation of the circle is 
We need to determine the center and radius of the circle.
<u>Center</u>:
The general form of the equation of the circle is 
where (h,k) is the center of the circle and r is the radius.
Let us compare the general form of the equation of the circle with the given equation
to determine the center.
The given equation can be written as,

Comparing the two equations, we get;
(h,k) = (0,-4)
Therefore, the center of the circle is (0,-4)
<u>Radius:</u>
Let us compare the general form of the equation of the circle with the given equation
to determine the radius.
Hence, the given equation can be written as,

Comparing the two equation, we get;


Thus, the radius of the circle is 8
Get like terms together. you might have to move across the equals sign
3x-x=-6+82
2x=76
x=38
Y = x^2 - 6x + 7
a = 1
b = -6
c = 7
Before you get the A.O.S, you must first solve for the vertex.
The vertex formula is \frac{-b}{2a}
Plug in the numbers:
-(-6) / 2(1)
--6 = 6 and 2*1 = 2
6/2
Vertex (or x) = 3
Now you have to plug in the x in order to find the vertex (or y)
Your equation should now look like this;
y = (3)^2 - 6 (3) +7
Solve each part separately and then add it up...
3^2 = 9
-6 * 3 = -18
+7
9 - 18 + 7
A.O.S (or y) = -2