# Thread: Another X in exponent question.

1. ## Another X in exponent question.

It states to to solve. The answer in the back of the book states that it's -1, 1. I just don't know where to start the questions.

3^(2x+1) - 10*3(^x)+3=0.

Oh by the way... how can I insert questions in proper format?

Thanks

2. ## Re: Another X in exponent question... this one seems tricky.

Originally Posted by conpark
It states to to solve. The answer in the back of the book states that it's -1, 1. I just don't know where to start the questions.
3^(2x+1) - 10*3(^x)+3=0.
Rewrite that as $3(3^x)^2-10(3^x)+3=0$.
Let $t=3^x$ solve $3t^2-10t+3=0$

3. ## Re: Another X in exponent question... this one seems tricky.

Originally Posted by conpark
3^(2x+1) - 10*3(^x)+3=0.
Oh by the way... how can I insert questions in proper format
You can learn to post in symbols, use LaTeX tags
$$3^{2x+1} - 10\cdot 3^{x}+3=0$$ gives

$3^{2x+1} - 10\cdot 3^{x}+3=0$

4. ## Re: Another X in exponent question... this one seems tricky.

Just as a quick review, Plato is using " $a^{x+y}= a^xa^y$ to change $3^{2x+1}$ to $3^{2x}3^1= 3(3^{2x})$ and $a^{xy}= (a^x)^y$ to change $3^{2x}$ to $(3^x)^2$.

5. ## Re: Another X in exponent question... this one seems tricky.

Thanks everyone! Wish I had found this forum earlier. It would have saved me a lot of time~

6. ## Re: Another X in exponent question... this one seems tricky.

HallsofIvy, is the solution simply 1 or -1 as well? I understand how to get one but the book states the solutions as -1 and 1, with the -1 listed first. Cheers

7. ## Re: Another X in exponent question... this one seems tricky.

Nevermind. I got it.