AMC 12 2018b Problem 3

A line with slope $2$ intersects a line with slope $6$ at the point $(40,30)$. What is the distance between the $x$-intercepts of these two lines?

$\textbf{(A) } 5 \textbf{(B) } 10 \textbf{(C) } 20 \textbf{(D) } 25 \textbf{(E) } 50$