I know how to solve this problem through just multiplying by two. I found that it was 9, but how would one solve this equation without going the long way? Such as:
Take the logarithm of both sides,
$\displaystyle \log 5^x = \log 625$
$\displaystyle x\log 5=\log 625$
$\displaystyle x=\frac{\log 625}{\log 5}$
Use calculator to compute the answer.