Find all points on the x-axis that are 1414 units from the point (5, −7).
they would lie on a circle of radius 1414 with center at (5,-7)
(x-5)^2 + (y+7)^2 = 1414^2
But, since you want points on the x-axis (y=0), that means
(x-5)^2 + 7^2 = 1414^2
So now just solve for x