a=(25)\mathbf{a} = \begin{pmatrix} 2 \\ 5 \end{pmatrix}a=(25) b=(4−1)\mathbf{b} = \begin{pmatrix} 4 \\ -1 \end{pmatrix}b=(4−1)
Work out 3a+b3\mathbf{a} + \mathbf{b}3a+b as a column vector.
