I am learning about natural logarithms and this is the first equation i must solve:

$$ 30 - 23 e^{-0.027x} > 20 $$

Could somebody explain what i should do to solve this and other equations like these? Thanks

  • $\begingroup$ The function $\ln$ (or $\log$ depending on how you write the natural logarithm) is the inverse of the function $\exp$. $\endgroup$ – mvw Feb 23 '15 at 14:06


Move the constant to right:


Divide with $-23$:


And now! You can soon get the log of both sides!


Good luck! And learn at least basic equation solving, without them all of such problems will be much harder!

  • $\begingroup$ log or ln ? If base is not mentioned log means to the base 10 $\endgroup$ – Vikram Feb 23 '15 at 14:20
  • $\begingroup$ @Vikram I learned $\ln{}$ as the natural logarithm in the basic school, but everywhere on the net I found this as $\log{}$. I think the $\ln{}$ would be better, but I must adapt the convention. $\endgroup$ – peterh Feb 23 '15 at 14:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.