A variable line xa+yb=1  is such that a – b = 14. The locus of the midpoint of the line intercepted between the axes is

Let P (x , y) be a point on the locusif A(a,0) B(0,b) then x=a+02 y=0+b2∴A=(2x,0),   B(0,2y)∴a=2x,    b=2y∴a−b=14⇒x−y=7∴  locus x – y = 7