Answer
(a) $(2,3,4)$ is a point on the line.
(b) $\langle 3,-2,5 \rangle$ is a direction vector
Work Step by Step
$(x,y,z) = (2,3,4)+n(3,-2,5)$
(a) We can find a point on the line:
When we let $n=0$, $(x,y,z) = (2,3,4)$
Therefore, $(2,3,4)$ is a point on the line.
(b) We can let $n=1$ to find a direction vector:
$\langle 3,-2,5 \rangle$ is a direction vector