Find the radius of a circle with the equation: x^2 + y^2 – 18x – 24y + 124 = 0
Complete the square for x and y
x^2 -18x + y^2 - 24 y = -124
(x-9)^2 + ( y -12)^2 = - 124 +81 + 144 <===== the red part = r^2
= 101 r = sqrt (101)
