Chapter 5 - Exponents and Polynomials - 5.6 - Integral Exponents and Scientific Notation - Problem Set 5.6 - Page 223: 28

$48$

Using the laws of exponents, the given expression, $ \left( 3^{-1}\cdot4^{-2} \right)^{-1} ,$ is equivalent to \begin{array}{l}\require{cancel} 3^{-1(-1)}\cdot4^{-2(-1)} \\\\= 3^{1}\cdot4^{2} \\\\= 3\cdot16 \\\\= 48 .\end{array}