CPM Homework Help : PC Problem 9-43

Simplify each of the following expressions.

$\frac { ( \sqrt { x ^ { 2 } + y ^ { 2 } } ) ^ { 3 } } { 2 \sqrt { x ^ { 2 } + y ^ { 2 } } }$
Hint (a):
$\text{Let }u = \sqrt{x^2 + y^2}.$
More Help (a):
$\dfrac{u^3}{2u}$

$\frac { 2 x ^ { 5 } - 8 x ^ { 3 } } { x + 2 }$
Steps (b):
1. Factor out a $2x^{3}$ in the numerator.
2. Factor the remaining binomial in the numerator.
3. Simplify.