Answer
$21i-2j-5k$
Work Step by Step
Let us consider two vectors $v=pi+qj+rz$ and $w=xi+yj+zk$; then we have:
$v+w=(p+x)i+(q+y)j+(r+z)k$
The magnitude of any vector (let us say $v$) can be determined using the formula
$||v||=\sqrt{p^2+q^2+r^2} $
Therefore,
$4v-3w=4 (3i+j+2k)-3(-3i+2j-k) \\
=12i+4j-8k+9i-6j+3k\\
=21i-2j-5k$
