Question 672303
  <pre><font face = "Tohoma" size = 3 color = "indigo"><b> 
Hi,
x^2+y^2+12x+10y+61=16
x^2+12x+y^2+10y= -45
x^2+12x+ <font color="red">36</font> + y^2 + 10y + <font color="green">25</font>  = -45 + <font color="red">36</font> + <font color="green">25</font> 
     {{{(x+6)^2 + (y+5)^2 = 16}}}  C(-6,-5)  and r = 4
Standard Form of an Equation of a Circle is {{{(x-h)^2 + (y-k)^2 = r^2}}} 
where Pt(h,k) is the center and r is the radius
{{{drawing(300,300,   -12, 6,-12, 6,  grid(1),
circle(-6, -5,0.2),
circle(-6, -5,4.0),
graph( 300, 300, -12, 6, -12, 6))}}}