You're not cancelling that out. You are done, this is the answer.

2. Originally Posted by Debsta
Thanks, Realistic. I successfully deleted my earlier comment.
Wasn't sarcasm before - a serious question
Factorise 2 out of the top to get 2(-1 +/- sqrt(7)) on top, then cancel 2 top and bottom.

3. Originally Posted by Debsta
Factorise 2 out of the top to get 2(-1 +/- sqrt(7)) on top, then cancel 2 top and bottom.
Ah you factorized the top bit thats what i was missing

cause i kept getting this answer

4. Bacterius, Go back to your comment. Hit edit and just delete everything. You don't seem to be able to clear evrything cause it sats your message is too short...so I just hit a key. Must be a better way. BTW your earlier comment re sqrt(28)=7 isn't there anymore anyway ...where'd it go?

Glad you got it now Realistic. Hope that helped.

Yes you factorize the top part, so the $2$ next to the root gets eliminated and the $-2$ becomes $-1$