Equation of the plane through the mid-point of the join of A(4,5,-10) and  B(-1,2,1) and perpendicular to AB is

Mid point of AB = 32,72,−92D.r’s of AB are (5,3,-11)Equation  of plane is r¯−(32i¯+72j¯−92k¯).(5i¯+3j¯−11k¯)=0  r¯.(5i¯+3j¯−11k¯)=1352