7 Three points have coordinates \(A ( 2,6 ) , B ( 8,10 )\) and \(C ( 6,0 )\). The perpendicular bisector of \(A B\) meets the line \(B C\) at \(D\). Find
- the equation of the perpendicular bisector of \(A B\) in the form \(a x + b y = c\),
- the coordinates of \(D\).