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# How to turn 8^9 into 2^x Watch

1. This is the question I'm working on - 2^30 / 8^9 = 2^x. Work out the value of x. My revision book has given me a tip saying "convert 8 to a power of 2 and then use the index laws". I can't remember how to do that, so could anyone remind me please?
2. 8= 2 x 2 x2 so 2^3

8^9= (2^3)^9= 2^27

2^x = 2^30/2^27 = 2^3
3. So how do you get 8 from 2?

Spoiler:
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2x2x2
4. 8 is 2^3. So (2^3)^9 is...
5. (Original post by AxSirlotl)
This is the question I'm working on - 2^30 / 8^9 = 2^x. Work out the value of x. My revision book has given me a tip saying "convert 8 to a power of 2 and then use the index laws". I can't remember how to do that, so could anyone remind me please?
Remember that , so then you are dealing with . From here, simply apply the division rule for indicies
6. Hmmm............ I'm not QUITE sure if someone else has already said it, but I THINK the fact that might help. Just a hunch though.
7. 8^9 = 2^x

8 = 2^3

8^9 = (2^3)^9

(a^b)^c = a^(b*c)

(2^3)^9 = 2^27
8. (Original post by AxSirlotl)
This is the question I'm working on - 2^30 / 8^9 = 2^x. Work out the value of x. My revision book has given me a tip saying "convert 8 to a power of 2 and then use the index laws". I can't remember how to do that, so could anyone remind me please?

there is a rule in ur book which goes something like this
therefore

so x = 3

Watch this video if you don't understand

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