The equation of the line passing through the origin and the point of intersection of the lines xa+yb=1 and xb+ya=1 is
(4)
Given equation of lines are
xa+yb=1, xb+ya=1
or bx+ay=ab ...(i)
ax+by=ab ...(ii)
Solving (i) and (ii),
x=aba+b, y=aba+b
So equation of line passing through (0,0) is
y-0=aba+baba+b(x-0)⇒y=x