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1. work out the value of x when

2^30/8^9=2^x

how would i do this
2. Replace 8 with 2^3.
3. (Original post by little_wizard123)
Replace 8 with 2^3.
ok so 2^30/2^3=2^x
4. (Original post by zed963)
work out the value of x when

2^30/8^9=2^x

how would i do this

Remember, , hence, can be written as
Now use the law,
5. (Original post by zed963)
ok so 2^30/2^3=2^x
No. You have replaced 8^9 by 2^3.

8^9 = (2^3)^9. Then simplify this with an indices rule.
6. (Original post by raheem94)

Remember, , hence, can be written as
Now use the law,
so 2^30-2^27=2^3
7. (Original post by zed963)
so 2^30-2^27=2^3
Is the '-' a typo?
It should be a divisor.

Yes, we get , but what is the value of
8. (Original post by raheem94)
Is the '-' a typo?
It should be a divisor.

Yes, we get , but what is the value of
Yeah it's a typo

x=3
9. 2^30 / 8^9 = 2^x
2^30 / (2^3)^9 = 2^x
2^30 / 2^27 = 2^x
2^3 = 2^x

x = 3
10. (Original post by zed963)
Yeah it's a typo

x=3

You are getting better at maths!
11. (Original post by kuroudo93)
2^30 / 8^9 = 2^x
2^30 / (2^3)^9 = 2^x
2^30 / 2^27 = 2^x
2^3 = 2^x

x = 3
You may like to have a look at the forum rules, full solutions are considered a last resort.

So always first give hints, please don't post full solutions.
12. just expand 2^30 and divide it by 8^9 and you'll get 8. therefore x is 3
13. (Original post by lmartynofficial)
just expand 2^30 and divide it by 8^9 and you'll get 8. therefore x is 3
Can you please clarify what do you mean by expand 2^30?
14. (Original post by lmartynofficial)
just expand 2^30 and divide it by 8^9 and you'll get 8. therefore x is 3
You make it sound easy.
15. (Original post by raheem94)
Can you please clarify what do you mean by expand 2^30?
I think he literally means do 2*2*2*2.... 30 times and write the value without indices. And then the same with 8^9
16. (Original post by hassi94)
I think he literally means do 2*2*2*2.... 30 times
My also guess was that he means this, but it doesn't looks sensible.

How will he divide by 8^9, any idea?
17. (Original post by raheem94)
My also guess was that he means this, but it doesn't looks sensible.

How will he divide by 8^9, any idea?
It is a pretty terrible solution to the problem.

Well you get 1073741824/134217728 and then he somehow sees that that = 8.

It's a silly solution, I wouldn't worry
18. (Original post by hassi94)
It is a pretty terrible solution to the problem.

Well you get 1073741824/134217728 and then he somehow sees that that = 8.

It's a silly solution, I wouldn't worry
That solution does actually work.
19. (Original post by hassi94)
It is a pretty terrible solution to the problem.

Well you get 1073741824/134217728 and then he somehow sees that that = 8.

It's a silly solution, I wouldn't worry
At least he isn't trying to use the infinity concept someone used yesterday. lol

OP, please ignore post#12.
20. (Original post by zed963)
That solution does actually work.
We know it works, but how will you do it without a calculator?
You won't be able to see that the value is 8 without a calc.

Updated: May 9, 2012
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