Question

What is the radius of a circle with the equation x2 + y2 – 14x + 10y = 250?

Answer 1

X2 + y2 - 14x + 10y = 250
x2 -14x + 49 - 49 + y2 + 10x + 25 - 25 = 250
(x - 7)^2 - 49 + (y+5)^2 - 25 = 250
(x-7)^2 + (y+5)^2 = 250 + 49 + 25
(x-7)^2 + (y+5)^2 = 324

Therefore the radius, r
r = 324^0.5
r = 18