You need to divide the terms `3sqrt2` and `3a` such that:
Notice that numerator `3sqrt2` and denominator `3a` have in common the factor `3` , hence, you may divide both by `3` such that:
`3sqrt2/(3a) = sqrt2/a`
Since the problem does not provides information about the number a, you may stop the division at this moment.
If a is is a radical number, you need to multiply by `sqrt a` to remove the radical from denominator.
If a represents an expression of form `root(n) x+ root(n) y,` you need to perform the multiplication by the conjugate of `root(n) x + root(n) y` to remove the radicals from denominator.
Hence, since there are no information about a and performing the division, yields `3sqrt2/(3a) = sqrt2/a.`