The equation of a circle is x2 + 8x + y2 - 12y = 144. What are the coordinates of the center and the length of the radius of the circle?

The centre is the point (-4,6).

The length of the radius is 14.

Step-by-step explanation:

The equation of a circle has the following format:

In which r is the radius and the centre is the point

In this question:

We have to complete the squares, to place the equation in the general format:

So

To complete the quares, we divide each first order term(8 and -12) by two, having two new terms(4 and -6). With this, we write as the square of (x+4) and (y-6). To compensate, we have to find the square of 4 and -6 on the other side of the equality.

The centre is the point (-4,6).

The length of the radius is

99

step-by-step explanation:

the answer is b.

step-by-step explanation: