The point of intersection of the lines `x/ay/b =1 and x/b +y/a =1` lines on the line

The point of intersection of the lines x/a+y/b =1 and x/b +y/a =1 lies on the line

The point of intersection of the lines x/a+y/b=1 and x/b+y/a=1 lies on

The point of intersection of the lines x/a+y/b=1 and x/b+y/a=1 lies on

The point of intersection of the lines x/a+y/b=1 and x/b+y/a=1 lies on

The point of intersection of the lines x/a+y/b=1 and x/b+y/a=1 lies on

The point of intersection of the lines x/a + y/b = 1 and x/b + y/a = 1 does not lie on the line

What is the equation on the straight line joining the origin to the point of intersection of the lines x/a+y/b=1 and x/b+y/a=1 ?