Two vectors are equal; they are the same in a magnitude and direction
The addition of three vectors obtains the resultant vector,
R = A + B + C
Vector Subtraction
The negative of a vector point in the opposite direction.
To find A-B, we add –B to vactor A
A-B = A+ (-B)
B-A= B+ (-A)
From the diagrams, we see that A-B ≠ B-A because it has an opposite direction, but the magnitude of A-B and B-A are equal.