Subtracting a vector is the same as adding a negative version of the vector (remember that making a vector negative means reversing its direction). \(\left( \begin{array}{l} a\\ b \end{array} ...

So the three ways to write this vector are: \(\overrightarrow {BA}\), -a and \(\begin{pmatrix} -3 \\ -4 \end{pmatrix}\). Subtracting a vector is the same as adding a negative version of the vector ...