Question 1138529
.
<pre>
{{{log(2,(x^2-9))}}} = {{{4}}}


is equivalent to


    {{{x^2-9}}} = {{{2^4}}}    (by the definition of the logarithm)


which, in turn, is equivalent to


    {{{x^2}}} = {{{16+9}}},   or

    {{{x^2}}} = 25.


Hence,  x = {{{sqrt(25)}}} = +/- 5.


<U>ANSWER</U>.  The given equation has two solutions,  x= 5  and  x= -5.
</pre>