To be a perpendicular bisector it must be both perpendicular and a bisector.
To be a bisector, it must pass through the midpoint of the line segment AB.
A formula for finding the midpoint of A(x1, y1) and B(x2, y2) is Midpoint = ( (x1 + x2)/2, (y1 + y2)/2 ).
---> Midpoint = ( (2 + 8)/2, (-1 + 3)/2 ) = (5, 1)
To be perpendicular, the slope of the line must be the negative reciprocal of the original line.
A formula for slope is: m = (y2 - y1) / (x2 - x1)
---> Slope = (3 - -1) / (8 - 2) = 4/6 = 2/3
---> Negative reciprocal of that slope: m = -3/2
Point-slope equation of a line: y - y1 = m(x - x1)
---> Point = (5, 1) Slope = -3/2
---> y - 1 = -3/2(x - 5)
---> 2y - 2 = -3(x - 5)
---> 2y - 2 = -3x + 15
---> 2y = -3x + 17
---> 3x + 2y = 17