You can put this solution on YOUR website! you can find the slope m1 of the line that goes through those two points
the new equation will have slope m2 which will be m1*m2=-1
the new line will goes through a point which is half the distance from those two points
when you have the bisector point you can plug the new ordered pair in the new equation y=mx+b where m=m2 and you will solve for b