Answer:
a. Center: (-15, 9), Radius: 5
Step-by-step explanation:
Equation of a circle:
The equation of a circle of center [tex](x_0, y_0)[/tex] and radius r is given by:
[tex](x - x_0)^2 + (y - y_0)^2 = r^2[/tex]
In this question, we have that:
[tex](x + 15)^2 + (y - 9)^2 = 25[/tex]
Comparing both equations:
[tex]x - x_0 = x + 15[/tex]
[tex]x_0 = -15[/tex]
And
[tex]y - y_0 = y - 9[/tex]
[tex]y_0 = 9[/tex]
The center is [tex](-15,9)[/tex].
For the radius:
[tex]r^2 = 25[/tex]
[tex]r = \sqrt{25} = 5[/tex]
The correct answer is given by option a.