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Traffik
Hi, I have a question. Your reasonings are all logic, but isn't the greatest prime factor of a number n the biggest prime number that divides n?
If this definition is correct, then 4^17 - 2^28 is actually divisible by 11, so wouldn't that make it the largest prime factor? Actually even 13 divides this number so i wouldn't know..
This is confusing me, maybe the definition is wrong, if somebody can explain it would be great.

4^17 - 2^28 is not divisible by 11 or 13. The largest prime it is divisible by is 7.
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Bunuel
Traffik
Hi, I have a question. Your reasonings are all logic, but isn't the greatest prime factor of a number n the biggest prime number that divides n?
If this definition is correct, then 4^17 - 2^28 is actually divisible by 11, so wouldn't that make it the largest prime factor? Actually even 13 divides this number so i wouldn't know..
This is confusing me, maybe the definition is wrong, if somebody can explain it would be great.

4^17 - 2^28 is not divisible by 11 or 13. The largest prime it is divisible by is 7.

I mean, maybe I have a problem with the concept of divisibility in english, but if you input (4^17-2^28) / 11 in you calculator, it comes an integer.
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Bunuel
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Hi, I have a question. Your reasonings are all logic, but isn't the greatest prime factor of a number n the biggest prime number that divides n?
If this definition is correct, then 4^17 - 2^28 is actually divisible by 11, so wouldn't that make it the largest prime factor? Actually even 13 divides this number so i wouldn't know..
This is confusing me, maybe the definition is wrong, if somebody can explain it would be great.

4^17 - 2^28 is not divisible by 11 or 13. The largest prime it is divisible by is 7.

I mean, maybe I have a problem with the concept of divisibility in english, but if you input (4^17-2^28) / 11 in you calculator, it comes an integer.

Use better calculator: https://www.wolframalpha.com/
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Why do we subtract 1?
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Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

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