Answer
$ -j$
Work Step by Step
Let us consider two vectors $v=pi+qj$ and $w=xi+yj$, then we have: $v \pm w=(p \pm x)i+(q \pm y)j$
The magnitude of any vector (let us say $v$) can be determined using the formula
$||v||=\sqrt{p^2+q^2+r^2} $
Therefore, $2v +3w= (6i-10j) +(-6i+9j) \\
= 6i-10j -6i+9j \\
= -j$
