There are several ways that ou could have intended. Some have direct solutions. Others don't. Use parentheses to clarify meaning.
e^x+3= pi^x Most critically, this means (e^x) + 3 = pi^x and cannot be solved directly.
We assumed you typed what you meant and came up with, e^x+3 = pi*e^x, which, being tranlsated tecnically is (e^x)+3 = (pi)*(e^x). This one can be solved directly.
The last guess was e^(x+3) = (pi)^x. This one can be solved directly.
So, it depends on what you mean.