If $ax^2+2hxy+by^2+2gx+2fy+c=0$ represents a pair of straight lines then show that the square of the distance from origin to their point of intersection is $\cfrac{c(a+b)-f^2-g^2}{ab-h^2}$
I could not figure out how to find the distance and how to show the required. Note; If you can please provide a solution with a figure.[IF POSSIBLE]