$${\left({\frac{{\mathtt{3}}}{{\mathtt{4}}}}\right)}^{\left(-{\mathtt{2}}\right)} = {\left({\left({\frac{{\mathtt{3}}}{{\mathtt{4}}}}\right)}^{{\mathtt{2}}}\right)}^{\left(-{\mathtt{1}}\right)}$$
$${\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}^{-{\mathtt{1}}} = {\frac{{\mathtt{1}}}{\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}}$$
$${\frac{{\mathtt{1}}}{\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}} = {\frac{{\mathtt{16}}}{{\mathtt{9}}}}$$
.$${\left({\frac{{\mathtt{3}}}{{\mathtt{4}}}}\right)}^{\left(-{\mathtt{2}}\right)} = {\left({\left({\frac{{\mathtt{3}}}{{\mathtt{4}}}}\right)}^{{\mathtt{2}}}\right)}^{\left(-{\mathtt{1}}\right)}$$
$${\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}^{-{\mathtt{1}}} = {\frac{{\mathtt{1}}}{\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}}$$
$${\frac{{\mathtt{1}}}{\left({\frac{{\mathtt{9}}}{{\mathtt{16}}}}\right)}} = {\frac{{\mathtt{16}}}{{\mathtt{9}}}}$$