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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

27^n+2 - 6*3^3n+3/3^n9^n+2

That is it.

Thanks.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

Okay, so far I have this,where is the mistake?

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

That's perfect no mistake!

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

How about doing some factoring there?

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

It says we should simplify it. But I don't know if it could be factorized. I tried doing it but the six has given me a tough time, it cannot be reduced to have 3 in order to have the same base as the others.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

How about simplifying 27^{3n+3} to start?

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

Okay,

= 3^3(n+2) = 3^(3n+6). You changed the exponent, please look at the original one above.

*Last edited by EbenezerSon (2013-07-23 07:19:10)*

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

I was thinking of

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**EbenezerSon****Member**- Registered: 2013-07-04
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At the back of the book the answer given was 21.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
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That is incorrect. If post #102 is correct the answer I am getting is 7. Please look closely at post #102 and make sure I have the right problem as you see it in your text book.

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

Yes, they are the ones in the book, the book could be wrong so please let proceed.

I have instances, I had my calculations correct while it had it wrong.

I will post a question I know I am correct while it has it wrong.

*Last edited by EbenezerSon (2013-07-23 07:59:38)*

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

Hi;

Answer is 7.

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

But I don't seem to understand those methods

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

Hi;

They are based on the laws of exponents. As far as I can see that is a tedious problem. There maybe something simpler but I can not see it.

What step is a problem?

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

This problem is from indices. So I had thought all the bases would be equal so I can take them off and simplify the exponent.

So I multiplied the six and the three which is eighteen and cannot be reduced to three, so that all the bases would be equall(to be three).

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

You mean multiple 6 * 3^(3n+3) ?

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

Yes to be > 18^(3n+3). But I see the eighteen cannot further be reduced to three, in order to have the same base with the others.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

That is incorrect. You can not say

6 * 3^(3n+3) = 18^(3n+3).

You can always test an idea by substituting some numbers for the variable. Try n = 1 and use a calculator.

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

Because so far all the problems I solved have the same bases, which is easy for me to take them off and simplify the exponent.

So I thought I could apply that on this problem.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

That is why I turned them all into the same bases, that way you can cancel and multiply when needed.

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

Then I need to learn the laws of exponents, or do indices also teaches that? If not then please could you assist me learn it?

Thanks for your assistance, God bless!

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

Yes, we can over the laws of exponents. Try here first.

Please look at these pages, they will help a lot.

http://www.mathsisfun.com/exponent.html

http://www.mathsisfun.com/algebra/varia … tiply.html

http://www.mathsisfun.com/algebra/exponent-laws.html

Do not worry if you can not absorb it all. It will come in time. Ask questions about anything you do not understand.

I am going to take a little break to do some chores be back later. Please look over those pages in the meantime.

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

A^n = A*A*A*.....A*

I think it should be impossible in that regard, because it has raised to the n. Meaning n is dividing the A, like n/A.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 88,903

A^n means A * A * A ... n times.

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**EbenezerSon****Member**- Registered: 2013-07-04
- Posts: 468

I have learnt that 5^0 = 1. Can you explain to me why it is equal to one?

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