Okay, do you know that when you have a product(s) equal to 0, you set each piece to equal zero. What I mean is:

If then or

Similarly:

or

So you know that one solution is , but there could be another one, when you solve the other equation.

You need to realize that the domain of the natural logarithm function is strictly greater than 0. Since the left side does not exist, there is no solution to this equation. (You might have noticed it before because exp(anything) can't equal 0.

This means your only solution is .

Hope I helped you