8n-(2n-3)=12
8n-2n+3=12
6n=12-3
6n=9
n=9/6=3/2
We don't have a pic. We need one
The standard equation of a circle is:

where (h,k) is the center and r is the radius.
We need to make an equation of a circle, whose center is (11,-5) with any radius. Therefore, substitute the value.

The bolded part is your answer. Since the radius is not given, we can put any value.
I think the answer to m is 8