Refer to the figure below.
Define unit vectors as follows:

in the eastern direction

in the northern direction
Given:
Vectors a and b point due west and south respectively. Therefore

Part (a)

The magnitude is
|-69(√[1² + 1²])| = 69√2 = 97.58.
The direction relative to west is
θ = tan⁻¹ (b/a) = tan⁻¹ 1 = 45° south of west
Answer:
The magnitude of (a + b) is 97.58 or 69√2.
The direction is 45° south of west.
Part (b).

The magnitude is
|69(√(1+1)| = 69√2 = 97.58.
The direction relative to west is
tan⁻¹ (b/a) = 45° north of west.
Answer:
The magnitude of (a-b) is 97.58 or 69√2.
The direction is 45° north of west.
Hey!
First, let's write the problem.

We know that,

, so let's apply that

We have to add,


We know that

, so let's apply that.

Subtract.

Our final answer would be 7!Thanks!
-TetraFish
A) is right
b) just subtract ljm and kjm so 145-48 = 92°
c) 9x-25=7x+7 so here you put npq=mpq+mpn and you combine terms so it's now 2x=32 then divide by 2 on both sides and x= 16
now you just plug it into 3x-5 and you get 43°