Answer
$\frac{1}{7x}$
Work Step by Step
The excluded values are x=0 because it makes the denominator zero.
Reduce $\frac{4x^{3}}{28x^{4}}$ by dividing by $\frac{4}{4}$.
$\frac{4x^{3}}{28x^{4}}$ $\div$ $\frac{4}{4}$ = $\frac{x^{3}}{7x^{4}}$.
Subtract the powers of x.
$\frac{x^{3}}{7x^{4}}$ = $\frac{1}{7x^{4-3}}$ = $\frac{1}{7x}$
