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Dividing exponents

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by ostrowskiamy » Mon Feb 18, 2013 5:06 pm
Hi there! Next question:

2^(4-1)^2 / 2^(3-2).

My answer = 2^5. Correct answer = 2^8. I thought I had to multiply the numerator's exponent of (4-1 = 3) by 2, to get 6, and then subtract 1 (the exponent that is the result of (3-2) in the denominator.

How does one reach 2^8?
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Source: — Data Sufficiency |

by Brent@GMATPrepNow » Mon Feb 18, 2013 6:12 pm
ostrowskiamy wrote:Hi there! Next question:

2^(4-1)^2 / 2^(3-2).

My answer = 2^5. Correct answer = 2^8. I thought I had to multiply the numerator's exponent of (4-1 = 3) by 2, to get 6, and then subtract 1 (the exponent that is the result of (3-2) in the denominator.

How does one reach 2^8?
I think there may be a problem with your use of brackets when transcribing the question.
If the correct answer is 2^8, then the original expression should look like this:
2^[(4-1)^2] / 2^(3-2)
Simplify 4-1 and 3-2 to get: 2^[3^2] / 2^1
Simplify 3^2 to get: 2^9 / 2^1
Apply quotient law to get: 2^8

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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by ceilidh.erickson » Tue Feb 19, 2013 11:05 am
Just to make this easier visually...


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Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
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