"a) Write [imath]\sqrt{27} + \sqrt{3}[/imath] in the form [imath]\sqrt{a}[/imath]." - This I had no issue with. [imath]\sqrt{48}[/imath] was my answer.

Followed by:

"b) Without using decimal approximations, explain whether [imath]\sqrt{27} - \sqrt{20}[/imath] is greater or less than [imath]\sqrt{5} - \sqrt{3}[/imath]."

How would I go about doing this? My attempts haven't worked at all, I'd appreciate any help.

Thanks in advance.