We always want to convert natural logs into easier logs, say log base ten. So that means we have to use this mathematical formula that relates bases of logs. And what we basically have to realize is that natural log of Q is the same thing as this guy divided by this guy. It's just a formula. You can look that up online. So we take this guy, we plug it into this Lnq and that means we are left with log base ten Q on the top.