Sorry, you're talking about "solving an equation", but 

1. An equation has to have an = sign somewhere in it but

"log5 62"  has no equal sign,

Also,

2. In order to "solve an equation" not only do you have to have
an equation, but the equation must also contain a variable such as x
or y to solve for. "log5 62" has neither and = nor an x

So not only is "log5 62" not an equation, it also has no variable to
solve for.  Post again, this time making sure what you type has both
an = sign as well as a variable letter such as x or y.

Edwin