Answer:
1.Orthogonal
2.Parallel
3.Neither
Step-by-step explanation:
We have to find pair of vectors are parallel , orthogonal or neither.
1.a=(-3,3,-5) and b=(-6,6,36/5)
We know that when vectors are parallel then,

When vectors are orthogonal then,





Hence, the vectors are not parallel.

Hence, the vectors are orthogonal.
b.a=(-3,3,-5), b=(-6,6,-10)




Hence, the vectors are parallel.
3.a=(-3,3,-5) and b=(12,-12,19)

Hence, the vectors are not orthogonal.




Hence, the vectors are not parallel.