Let $D_1$ and $D_2$ be two distinct lines in $\mathbb{P}^3$. Show that there is a homography $h$ such that $h(D_1)=V(X,Y)$ and $h(D_2)=V(Z,T)$.
I don't know how to find the homography. I know that $h:=z\mapsto \frac{az+b}{cz+d}$ is an homography. But how to show homography between $D_1$ and $V(X,Y)$? Similiarly, for $D_2$ and $V(Z,T)$?