0\\\\16^{x}=(4^{x})^{2}=m^{2} \\\\m^{2}-2m-8=0\\\\D=(-2)^{2}-4*(-8)=4+32=36=6^{2}\\\\m_{1}=\frac{2+6}{2}=4\\\\m_{2}=\frac{2-6}{2}=-2<0\\\\4^{x}=4\\\\x=1" alt="16^{x} -2*4^{x}-8=0\\\\4^{x}=m,m>0\\\\16^{x}=(4^{x})^{2}=m^{2} \\\\m^{2}-2m-8=0\\\\D=(-2)^{2}-4*(-8)=4+32=36=6^{2}\\\\m_{1}=\frac{2+6}{2}=4\\\\m_{2}=\frac{2-6}{2}=-2<0\\\\4^{x}=4\\\\x=1" align="absmiddle" class="latex-formula">