24. Identify the center and radius of the circle given the equation (x +15)2 + (7 - 9)2 = 25 .
a. Center: (-15, 9), Radius: 5
b. Center: (15, -9), Radius: 25
c. Center: (-15, -9) Radius: 5
d. Center: (15,9) Radius: 25

Respuesta :

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.