What do I do when log x is equal to a number?

$$\\log x=y\\ then\\ x=10^y\\\\ eg\\ logx={17}\\ x=10^{17}$$

What do I do when log x is equal to a number?

Well, it means you got the answer that you wanted!!!!.

"Log" is just another name for "exponent"

10^2. In this case 2 is the Log or Exponent of 10;

So, if we had 10^x=100. To find x, we take the log of both sides;

so, Log(10^x)=Log(100)

We isolate x Log 10=Log(100)

x * 1=2,  or x=2/1=2