[zed963]

work out the value of x when

2^30/8^9=2^x

how would i do this

[little_wizard123]

Replace 8 with 2^3.

[zed963]

(Original post by little_wizard123)
Replace 8 with 2^3.

ok so 2^30/2^3=2^x

[raheem94]

(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,

[little_wizard123]

(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.

[zed963]

(Original post by raheem94)


Remember, , hence, can be written as
Now use the law,

so 2^30-2^27=2^3

[raheem94]

(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

[zed963]

(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

[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

[raheem94]

(Original post by zed963)
Yeah it's a typo

x=3

You are getting better at maths!

[raheem94]

(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.

[lmartynofficial]

just expand 2^30 and divide it by 8^9 and you'll get 8. therefore x is 3

[raheem94]

(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?

[Intriguing Alias]

(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.

[Intriguing Alias]

(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

[raheem94]

(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?

[Intriguing Alias]

(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

[zed963]

(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.

[raheem94]

(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.

[raheem94]

(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.