If the lines 
1
2
3
1
1
6
and
3
2
2
3
1
5
x
y
z
x
y
z
k
k
−
−
−
−
−
−
=
=
=
=
−
−
 are perpendicular,,
find the value of k 7 Find the vector equation of the line passing through (1, 2, 3) and perpendicular to
the plane 
0
9
)ˆ
5
2ˆ
ˆ
( =
+
−
+
k
j
i
rr