Answer
$-\frac{4}{x}$
Work Step by Step
$\frac{20x^3}{-5x^4}$
Apply the fraction rule: $\frac{a}{-b} = -\frac{a}{b}$
Hence, $\frac{20x^3}{-5x^4}$ = $-\frac{20x^3}{5x^4}$
$=-\frac{4x^3}{x^4}$
Recall that $\frac{a^m}{a^n} = \frac{1}{a^{n-m}}$
Thus,
$-\frac{4x^3}{x^4}= -\frac{4}{x^{4-3}}$
$=-\frac{4}{x}$
