Chapter 5 - Section 5.2 - Negative Exponents and Scientific Notation - Exercise Set - Page 354: 59

$\dfrac{-12m^{5}n^{-7}}{4m^{-2}n^{-3}}=\dfrac{-3m^{7}}{n^{4}}$

$\dfrac{-12m^{5}n^{-7}}{4m^{-2}n^{-3}}$ Evaluate the division: $\dfrac{-12m^{5}n^{-7}}{4m^{-2}n^{-3}}=\Big(\dfrac{-12}{4}\Big)m^{5-(-2)}n^{-7-(-3)}=-3m^{7}n^{-4}=...$ Simplify: $...=\dfrac{-3m^{7}}{n^{4}}$