How do I solve an exponential equation with different bases?

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babacanoosh
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Hello all, I can't believe I having a hard time with this problem but...I am :cry:1. 2^(x^2) X 4^(2x) = 1/8
2. make the bases the same?
3.
2^(x^2) X 2^((2x)^2) = 1/8
2^(3x^(2)) = 1/8
3x^(2)log2=log1/8
(log1/8)/(log2) = 3x^(2)
x^(2) = -1


I know I am doing it wrong. Any help would be greatly appreciated. Thanks,
Baba
 
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The general rule for "exponentiated exponents" is

[tex](a^b)^c = a^{(b \cdot c)[/tex], for a positive base a .

For this problem, you will end up with a quadratic equation in x, with two solutions.
 
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great! thanks so much. Just a stupid mistake on my part, I knew that :rolleyes:
 
I believe you end up with two imaginary solutions; My guess is that you should just show your work until you run into negative square root.
 
epkid08 said:
I believe you end up with two imaginary solutions; My guess is that you should just show your work until you run into negative square root.

You actually get two real roots.
 
I found the same, you should get two real roots.
 
Oh, I see what I did wrong, I had [tex]2^{x^2}(2^x + 2^x)=1/8[/tex], instead of [tex]2^{x^2}*2^x*2^x=1/8[/tex]