CPM Homework Help : PC Problem 5-76

Simplify: $( \frac { x ^ { - 2 } + x ^ { - 1 } } { x + x ^ { - 3 } } ) ^ { - 1 }$

Step 1:

$\left( \frac { x + x ^ { - 3 } } { x^{-2} + x ^ { - 1 } } \right) ^ { - 1 }$

Step 2:

$\frac { x + \frac{1}{x ^ { 3 } }} { \frac{1}{x^2} + \frac{1}{x} }$

Step 3:

$\left( \frac { x + \frac{1}{x ^ { 3 } }} { \frac{1}{x^2} + \frac{1}{x} } \right)\left(\frac{\frac{x^3}{1}}{\frac{x^3}{1}}\right)$