I am not positive this is the correct spot for this question ( it is an Algebra question but it was not given in the context of an Algebra class. I am currently working my way through Michael Spivak's book "Calculus"). Here is the question:

$\displaystyle

x + 3^x<4

$

Now just by looking at it, I can see that the answer has to be x<1 but I don't see how I could show that mathematically. Any insights would be appreciated.

Dag