Question 377568
{{{5^x+5^(-x)=2}}}
{{{5^x+1/5^(x)=2}}}
Let {{{y=5^x}}}
{{{y+1/y=2}}}
{{{y^2+1=2y}}}
{{{y^2-2y+1=0}}}
{{{(y-1)^2=0}}}
{{{y-1=0}}}
{{{y=1}}}
{{{5^x=1}}}
{{{highlight(x=0)}}}