0\\a^2-5a-6=0\\a_1=6\ \ \ \ ;a_2=-1\\(\frac{1}{6})^x=6\ ;error\\x=-1" alt="( \frac{1}{6}) ^{2x} -5*( \frac{1}{6}) ^{x} -6=0\\\frac{1}{6}^x=a;a>0\\a^2-5a-6=0\\a_1=6\ \ \ \ ;a_2=-1\\(\frac{1}{6})^x=6\ ;error\\x=-1" align="absmiddle" class="latex-formula">