slope of the line with points (4,-1) and (-3,5)
slope = (5 - -1)/(-3 -4)
slope = 6/-7
slope = -6/7
since the product of gradients of perpendicular lines is -1 .
then m x -6/7 = -1 where m is the gradient of the required lined
therefore m = 7/6
therefore the slope is 7/6