First, we can divide both sides by 2. So, we started with
2e^x = 1
and then dividing by 2 we get
e^x = 1/2
To get the x by itself, we need to take the natural log (ln) of both sides, since ln(e) = 1 so we will be left with x.
That means,
x = ln(1/2) = -0.69