Find the radical centre of circles

MATHEMATICS · Subjective · A Level · Mathematics · Coordinate geometry in the (x y) plane · Coordinate geometry in the (x y) plane

Problem

x^2 + y^2 + 3x + 2y + 1 = 0

x^2 + y^2 - x + 6y + 5 = 0

and

x^2 + y^2 + 5x - 8y + 15 = 0

. Also, find the equation of the circle cutting them orthogonally.