3^2x+1 + 3^x+2= 12 Prove?
Please look over your expression as it's not clear what you want.
The way you have written your expression I get
I suspect you mean
But please ensure that the expression is actually what you mean.
Also: Prove that this expression is true? I think you mean that you want it solved.
Incidentally I get that if the last expression is what you mean, then
This last has a complex root, and it is so long since I worked with complex numbers, so I am not totally sure what x will be if this is correct.