Hello everybody

I am rehearsing my skills with fractions, square roots and potencies. I have got a couple of problems and simplifications I'd like you to check and see if I am correct.

(first try with Latex...)

$\displaystyle \frac{2(frac{4}{3}$

Ok another go...

Problem 1

$\displaystyle \frac{2(-(4\div3)\times5\div2)}{-(8\div3)}$

I hope you can make out what I try to put in Latex language:

http://www.imageupload.se/files/070906/8778problem%201.JPG

Note: Space in url, copy and paste recommended.

Problem 2

$\displaystyle \frac{5\div6}{-(1\div6)}$ (I can't solve this one)

Problem 3

$\displaystyle \frac{2x+3}{4x^2-9}$ (ditto)

Problem 4 (another simplification)

$\displaystyle 4\sqrt12 + 3\sqrt 18 - \sqrt 50 - 2\sqrt 48$

Problem 5

$\displaystyle \sqrt\frac{2}{3}(\sqrt6-\sqrt3)$

All replies are welcome

EDIT: NOTE. Problem 4 is modified, I wrote it incorrectly

P.S.

I'll add my solutions later, writing these problems took enough time.