Suppose that the points (h,k)(1,2) and (−3,4) lie on the line L1. If a line L2 passing through the points (h,k) and (4,3) is perpendicular to L1 , then hk equals

Given points (1,2) (-3,4) and (h,k) are lies on line L1.So slope of line L1 is m1=4−2−3−1=k−2h−1h+2k=5.........(1)Slope of line L2 joining points (h,k) and (4,3) is m2=3−k4−hSince, lines L1 and L2 are perpendicular m1m2=−1    −123−k4−h=−12h−k=5...........(1)On solving Equs (1) and (2) we get (h,k)=(3,1)hk=3