I do not understand how to do logs in the form of just: log 12. I know how to do it with the subscripts, however. Please help

If a log has no base (subscript) specified, it is to be assumed the base is 10.

10

What do you mean? How do you do it? Assuming that it is in base ten does not change anything in my mind.

Do you know how to do this: log_{10}(12) ?

No, but I do know that would equal 10^x=12. I just don't know how to go from there