$15-16$ Determine whether the line and plane are parallel, perpendicular, or neither.

$15.($a$)$

ough the point

$x=4+2t,y=-t,z=-1-4t$

$3x+2y+z-7=0$

$($b$)$

$x=t,y=2t,z=3t$

$x-y+2z=5$

$($c$)$

$x=-1+2t,y=4+t,z=1-t$

$4x+2y-2z=7$

$($a$)$

$x=3-t,y=2+t,z=1-3t$

$2x+2y-5=0$

$($b$)$

$x=1-2t,y=t,z=-t$

$6x-3y+3z=1$

$($c$)$

$x=t,y=1-t,z=2+t$

$x+y+z=1$