Answer: The co-ordinates of the center of the circle are (-7, -1) and the length of the radius is 6 units.
Step-by-step explanation: Given that a circle is described by the following equation :

We are to find the co-ordinates for the center and the length of the radius of the given circle.
The STANDARD equation of a circle with center (h, k) and radius of length r units is given by

From equation (i), we have

Comparing with the standard form, we get
center, (h, k) = (-7, -1) and radius, r = 6 units.
Thus, the co-ordinates of the center of the circle are (-7, -1) and the length of the radius is 6 units.