Question 17
Distinct lines $\ell$ and $m$ lie in the $xy$-plane. They intersect at the origin. Point $P(-1, 4)$ is reflected about line $\ell$ to point $P',$ and then $P'$ is reflected about line $m$ to point $P''.$ The equation of line $\ell$ is $5x - y = 0,$ and the coordinates of $P''$ are $(4,1).$ What is the equation of line $m?$