Vector subtraction reverses the direction of the second vector

Scalars & Vectors — AQA A-Level Physics

To subtract vector b from vector a, reverse the direction of b to get -b.
Then add a and -b using the triangle or parallelogram method.
This is used when finding changes in velocityThe rate of change of displacement. A vector quantity. Measured in m s⁻¹.: $\Delta v = v - u requires subtracting$ the initial velocityThe rate of change of displacement. A vector quantity. Measured in m s⁻¹. vector.