If l, m, n are in AP, then the line lx+my+n=0` will always pass through the point

If a,b and c are in AP, then the straight line ax+by+c=0 will always pass through a fixed point whose coordinates are

IF a,b,c are in A.P then the striaght line ax+by+c=0 will always pass through a fixed point. Find it.

If A, B and C are in AP, then the straight line Ax + 2By+C =0 will always pass through a fixed point. The fixed point is

If l,m,n are in A.P then the liens represented by lx+my+n=0 are concurrent at the point

If I,m,n are in A.P then the lines represented by lx+my+n=0 are concurrent at the point

Find the locus of the circumcentre of a triangle whose two sides are along the co- ordinate axes and third side passes through the point of intersection of the lines ax+by+c=0 and lx+my+n=0