Question

(\frac{6}{r^{-5}t^{-1}})

Explanation:

Step1: Rewrite negative exponents

Recall $x^{-n}=\frac{1}{x^n}$, so $r^{-5}=\frac{1}{r^5}$, $t^{-1}=\frac{1}{t}$.
The denominator becomes $\frac{1}{r^5} \cdot \frac{1}{t} = \frac{1}{r^5 t}$

Step2: Divide by the fraction

Dividing by a fraction is multiplying by its reciprocal:
$6 \div \frac{1}{r^5 t} = 6 \cdot r^5 t$

Answer:

$6r^5 t$