here's the tricky little problem.. i have no idea how to solve this!
x-(x+h)
-----------
2(x+h)(x)
----------------
h
There's nothing to solve. What's the question?
Is it the following fraction?
$\displaystyle
\frac{{\frac{{x - \left( {x + h} \right)}}{{2\left( {x + h} \right)x}}}}{h}
$
Then you can simplify:
$\displaystyle
\frac{{\frac{{x - \left( {x + h} \right)}}{{2\left( {x + h} \right)x}}}}{h} = \frac{{ - h}}{{2\left( {x + h} \right)x}}\frac{1}{h} = \frac{{ - 1}}{{2\left( {x + h} \right)x}}
$