Exponential Equation In Quadratic Form

chillfactor

1. The problem statement, all variables and given/known data
The problem is 3^2x+3^(x+1)-4=0

I know I had to solve it by substitution


2. Relevant equations



3. The attempt at a solution
I had u = 3^x
I put it in:
(u )(u ), but I was not sure how to get the middle term 3^(x+1)

llello

You could write 3^(x+1) = 3^x * 3^1

Mentallic

chillfactor, that's a bad way to do it. Take this slowly, step by step.
First make the substitution, then once it is in the general quadratic form [tex]au^2+bu+c=0[/tex] THEN solve for u either by factorizing or using the quadratic formula. After doing that, substitute back in and solve for x.