SOLUTION: Hello, since I can't find an exponential equation topic, I'm going to ask here. What's the solution of the following equation? . the 2x+2 is above the '3', i put it in brackets for

Algebra ->  Logarithm Solvers, Trainers and Word Problems -> SOLUTION: Hello, since I can't find an exponential equation topic, I'm going to ask here. What's the solution of the following equation? . the 2x+2 is above the '3', i put it in brackets for      Log On


   

Question 1075151: Hello, since I can't find an exponential equation topic, I'm going to ask here. What's the solution of the following equation? . the 2x+2 is above the '3', i put it in brackets for easier understandment. Thanks for your help! [somewhy it didn't allow me to put the equation in curly braces]
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
3(^2x+2)-28*3^x=-3
3^(2x+2)-28*3^x=-3
3%5E%282x%2B2%29-28%2A3%5Ex+=+-3
9%2A3%5E%282x%29-28%2A3%5Ex+%2B+3+=+0
Sub u for 3^x
9u%5E2+-+28u+%2B+3+=+0
(9u - 1)*(u - 3) = 0
u = 3
3^x = 3
x = 1
===============
u = 1/9
3^x = 1/9
x = -2