2eˣ - 7 = 21
2eˣ = 28
eˣ = 14 How do we isolate for x now? Well we know that aˣ=b can be converted to [tex]x=log_{a}(b)[/tex].
x = [tex]log_{e}(14)[/tex] A shorthand for "log base e" is the natural log (ln).
x = ln(14)
x = 2.64 approx.
Exact answer: ln(14)
Approximation: 2.64