Let $\mathbf a = \langle -3, 1, -3 \rangle$ and $\mathbf b = \langle 3, 5, 0 \rangle$. Compute:

$\mathbf a + \mathbf b$ = (,,)
$\mathbf a - \mathbf b$ = (,,)
$2\mathbf a$ = (,,)
$3\mathbf a + 4\mathbf b$ = (,,)
$|\mathbf a|$ =