Question 705922
Use distance formula to calculate the radius, the length from the point on the circle, (-1,7), and the center, (-5,3).  

Using r for radius, {{{r=sqrt((-1-(-5))^2+(7-3)^2)}}}
={{{sqrt((4)^2+(4)^2)}}}={{{sqrt(32)}}}


Your circle's equation is {{{(x+5)^2+(y-3)^2=r^2}}}, and you can find r^2 from the previous use of the calculation of r.