5)a)(-15, 36)
b)(10,-24)
c)Not sure if there's supposed to be 2, but here goes: (48, 20) and (-48, -20)
And yes, I did all of this to raise my post count.
Edit: Magnitude = 13
Parallel means same direction, but it had to be 3x larger, so I multiplied by 3.
Opposite means, well, opposite direction, so I changed the signs. It had to be 2x the magnitude, so I multiplied by 2.
Orthogonal means at a right angle to, or perpidicular to. So, I found the slope of the first vector was -5/12. Therefore, the slope of the vector I was looking for was 12/5. However, it had to be 4x larger, so I multiplied by 4. I put the second one on there, (-48, -20), because it is opposite to the first one I found.