---You probably know that subtraction is the same thing as adding a negative: 8 – 5 is the same thing as 8 + (–5). The easiest way to think about vector subtraction is in terms of adding a negative vector. What’s a negative vector? It’s the same vector as its positive counterpart, only pointing in the opposite direction.

A – B, then, is the same thing as A + (–B). For instance, let’s take the two vectors A and B:

To subtract B from A, take a vector of the same magnitude as B, but pointing in the opposite direction, and add that vector to A, using either the tip-to-tail method or the parallelogram method.