Let $g(x)=\frac{10}{x}$.  

1. the average rate of change of $g(x)$ from $x=5$ to $x=6$.

   Step (a):

   $\frac{\frac{10}{6}-\frac{10}{5}}{6-5}$

2. Write the expression for the average rate of change of $g(x)$ from $x=5$ to $x=5+h$.

   Step (b):

   $\frac{\frac{10}{5+h}-\frac{10}{5}}{5+h-5}$

3. as $h→0$.

   Step (c):

   $\lim \limits_{h\rightarrow 0}-\frac{2}{5+h}=?$