Question 47860
graph x^2+y^2+8x-24y+16=0 
Complete the square on the x terms and on the y terms separately.

x^2+8x+16 + y^2-24y+144 = -16+16+144

(x+4)^2 + (y-12)^2 = 144

This is the equation of a circle with center at (-4,12) and radius = 12

Cheers,
Stan H.