Correct Answer - A
`x/a+y/b=1` ...(i)
and `x/b+y/a=1` ...(ii)
From solving equations (i) and (ii), we get the intersection point.
`bx+ay=ax+by`
`implies (b-a) x=(b-a) y`
`:. x=y` ...(iii)
`implies x/a+b/x=1`
`:. x(a+b)=ab`
`:. x=(ab)/(a+b) and y=(ab)/(a+b)` from equation (iii)
Now, equation of line joining (0, 0) and `((ab)/(a+b), (ab)/(a+b))`
Here, slope of line `=1`
`:. y=x`
`:. x-y=0`
`:.` Option (a) is correct.
