Adding Scalar Multiples of Vectors Graphically

[Turtlie]

Homework Statement

Draw the vector C = 1.5A -3B
(Mastering Physics problem)
A is 4.5 and B is 1.0

The Attempt at a Solution

I've tried it 4 times and still can't do it. I've looked at some sites but I guess I just don't understand it. I've heard of the head to tail method, or something similar, but I either did it wrong or didn't understand it.

I got the first one right, but I've never done any with the different-angled vectors (aside from East/West, North/East)

Oops, picture would be helpful.

 

[Delphi51]

Make A 1.5 times as long.
Make B 3 times as long and in the opposite direction to form -3B.
Copy the extended -3B so that it begins at the end of 1.5A. The total is the new vector going from the beginning of 1.5A to the end of the relocated -3B. Looks like about 9 to the right and 3 up.

 

[Turtlie]

1. Make A 1.5 times as long.
2. Make B 3 times as long and in the opposite direction to form -3B.
3. Copy the extended -3B so that it begins at the end of 1.5A.
4. The total is the new vector going from the beginning of 1.5A to the end of the relocated -3B. Looks like about 9 to the right and 3 up.

Is that right? Not completely sure about four though

 

[Delphi51]

Looks good! Ignore 4. Count your answer from the beginning of 1 to the tip of 3. It is 9 squares to the right and 4 squares up. Often written as (4,3).

 

[Turtlie]

Wait so which arrow would be the answer? The one that I labeled as 3?

Edit: Well 3 isn't the answer. I tried that one so now I have like 1 try left.