Okay, so here's my next drama:

Attachment 30691

It says the answer is: '√10a / 10'

However, how I am solving it is either multiplying either side by 2, then multiplying both sides again by the root 40 to rationalize the denominator.

The other way, dividing a/1 ÷ √40/2, then rationalizing, which gives me same wrong answer.

I've tried searching for ways to solve this type of question, but can't find anything. So please, how do I do this correctly?