
Surds
So I haven't had alot of time with my surds, and I'm basically stuck on the principals, I sorta see where I'm going but then somehow its all wrong (Worried)
I'll just show a few examples, then see if someone could explain it about (if you can =) )
2 /8  2 root 8
2/18 + 6  6/2
2 root 18 plus 6  6 root 2
/27  /3  2/12
root 27  root 3  2 root 12
Family has gone away the weekend, so no one I can really ask :S
Thanks you.

I don't know what you want to do but if it is to eliminate a root from the denominator you need to multiply by the conjugate.
EG $\displaystyle \frac{2}{8  2 \sqrt{ 8 }} = \frac{2}{8  2 \sqrt{ 8 }} \times \frac{8 + 2 \sqrt{ 8 }}{8 + 2 \sqrt{ 8 }}$
$\displaystyle \frac{16+4 \sqrt{8}}{64  16 \sqrt{ 8 }+ 16 \sqrt{ 8 } 32} =\frac{16+4 \sqrt{8}}{32} $
$\displaystyle \frac{4+ \sqrt{4\cdot 2}}{8}=\frac{4+ \sqrt{4}\sqrt{2}}{8}= \frac{4+ 2\sqrt{2}}{8}=\frac{2+ \sqrt{2}}{4}$