Hi!

4^(x+1) + 3 * 4^x = 112

Should I use log or something?

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- Mar 24th 2008, 01:47 PMTwigI have 4^(x+1) .. how to proceed
Hi!

4^(x+1) + 3 * 4^x = 112

Should I use log or something? - Mar 24th 2008, 02:02 PMJhevon
- Mar 24th 2008, 02:08 PMTwighi
I did solve it, but I doubt I did it "correctly".

I got 4 * 4^x + 3 * 4^x = 112

I divided all terms with 4^x

so I have 7 = 112/4^x

this gives me 4^x = 112/7

now I used logarithms to solve for x - Mar 24th 2008, 02:10 PMJhevon
- Mar 24th 2008, 02:13 PMTwig
hi

so I can basically say that 4 * 4^x + 3* 4^x = 7 * 4^x ?

and just from there take 112/7 = 16

and 4^x = 16 - Mar 24th 2008, 02:14 PMJhevon
- Mar 24th 2008, 02:16 PMTwig
x = 2

- Mar 24th 2008, 02:17 PMJhevon
- Mar 24th 2008, 02:19 PMTwig
thanks a lot

Yes I did.

I just didnt realize at first that I can add up my 4^x terms so I get 7 * 4^x - Mar 24th 2008, 02:21 PMJhevon
- Mar 24th 2008, 02:21 PMTwig
alright cool =)