Como se desarrolla esta operaacion 5^x=8^x

Como se desarrolla estas operacion: 

1.  $${{\mathtt{5}}}^{{\mathtt{x}}} = {{\mathtt{8}}}^{{\mathtt{x}}}$$

2.  $${{\mathtt{9}}}^{{\mathtt{x}}}{\mathtt{\,-\,}}{\mathtt{4}}{\mathtt{\,\times\,}}{{\mathtt{3}}}^{{\mathtt{x}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3}} = {\mathtt{0}}$$

3.  $${{\mathtt{3}}}^{\left({{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{x}}{\mathtt{\,-\,}}{\mathtt{12}}\right)} = {\mathtt{1}}$$