$($a$)$ Find symmetric equations for the line that passes through the point $(3,-4,9)$ and is parallel to the vector $(-1,3,-4).$

$($b$)$ Find the points in which the required line in part $($a$)$ intersects the coordinate planes.

point of intersection with $xy-$plane

point of intersection with $yz-$plane

point of intersection with $xz-$plane