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# C1 Indices Question HELP! Watch

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1. Hi,

Please Could anyone help (with method) how to solve for x (answer is 2)

2^2x - 6(2^x+1) + 32 = 0
(2 to the power of 2x minus 6 multiplied by 2 to the power of x+1 plus 32)

Thanks for the help!
2. (Original post by umbrocurry)
Hi,

Please Could anyone help (with method) how to solve for x (answer is 2)

2^2x - 6(2^x+1) + 32 = 0
(2 to the power of 2x minus 6 multiplied by 2 to the power of x+1 plus 32)

Thanks for the help!
So.... ??
3. (Original post by umbrocurry)
Hi,

Please Could anyone help (with method) how to solve for x (answer is 2)

2^2x - 6(2^x+1) + 32 = 0
(2 to the power of 2x minus 6 multiplied by 2 to the power of x+1 plus 32)

Thanks for the help!
You should know that

Your equation becomes: which you can solve for and then on its own.

4. Remember that
So can be written as
5. (Original post by RDKGames)
You should know that

Your equation becomes: which you can solve for and then on its own.

Yes but how can I solve as I can't get all the base numbers equal- 32 is 2^5 but then I am left with 12??
6. (Original post by Daffy786)
Yes but how can I solve as I can't get all the base numbers equal- 32 is 2^5 but then I am left with 12??
What does that even mean?? Just solve it as you would solve any quadratic - factorise it, or complete the square if needed.
7. (Original post by RDKGames)
What does that even mean?? Just solve it as you would solve any quadratic - factorise it, or complete the square if needed.
yes but how exactly?
8. (Original post by umbrocurry)
yes but how exactly?
Let

Then when you have y=something just replace y with and take logs with base 2 of both sides to get
9. (Original post by RDKGames)
Let

Then when you have y=something just replace y with and take logs with base 2 of both sides to get
Oh Yeah!!! Thanks so much! I forget substitution and I finally got the answer now.

On a side note: why is (2^x)^2 equal to 2^2x and not 4^2x, since surely you would have to square the integer too?

Thanks alot
10. (Original post by umbrocurry)
Oh Yeah!!! Thanks so much! I forget substitution and I finally got the answer now.

On a side note: why is (2^x)^2 equal to 2^2x and not 4^2x, since surely you would have to square the integer too?

Thanks alot
Simple GCSE index rule you're forgetting whereby

It cannot be since which makes no sense as to where the 4 comes from
11. (Original post by RDKGames)
Index rule you're forgetting whereby

It cannot be since which makes no sense as to where the 4 comes from
Oh yes of Course! I think it is because i was getting confused between (2^x)^2 and (2x)^2 (which of course equals 4x^2).

Thanks alot bro

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