Solving for x in an exponential function

[Linty Fresh]

Could someone give me a little push getting started on this little gem?

3^2x+3^(x+1)-4=0 Solve for x

I know I can convert 3^2x to (3x)^2 or (3^2)^x -->9^x, but I don't see how that would help me out solving for x on this one. I don't need it solved (I'm actually teaching myself algebra), but could someone give me a hint as to how to begin? Thanks so much.

Also, is there a way to use subscripts and superscripts so that I could get rid of the carets? Thanks.

 

[Matt]

Hi Linty,

Rewrite the equation as:

. . . . 3^2x + 3 * 3^x - 4 = 0

and substitute u = 3^x to obtain:

. . . . u²+ 3u - 4 = 0

Now solve for u.

 

[Linty Fresh]

You're the man, Matt. Thanks.

And I loved San Jose when I was there.