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Exponents

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Exponents

by azarkin » Tue Jul 15, 2014 5:50 pm
Which of the Following is equal to 10^(-(-3)^2)?

Could you help, im doing it and i get for an answer 10^6, but the gmat prep pack answer says its 1/10^9

Please Help
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by [email protected] » Tue Jul 15, 2014 6:01 pm
Hi azarkin,

This question is based on a set of rules called "order of operations" - the order in which you are supposed to "do math"

Here, we have 10 raised to a complicated-looking exponent. If we follow the rules though, the math itself won't be difficult...

First, we deal with (-3)^2...

(-3)^2 = 9

Next, we have to deal with the "extra" minus sign. This gives us...

-9

Finally, we have 10^(-9)

This can be rewritten as 1/10^9

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by unknown13 » Tue Jul 15, 2014 8:00 pm
Hi
The correct answer is 1/(10)^9
according to the PEMDAS rule
solve exponents which is (-(-3)^2) = (-(9)) = -9
now 10^(-9) = 1/10^9

thanks and regards
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by phanikpk » Tue Jul 15, 2014 9:09 pm
In case of a^m^n, the n power belongs to m but not to a

Similarly 10^(-(-3)^2)

First of all we have to remove the first - sign by transferring the power to denominator

This will give 1/10^(-3)^2

Then (-3)^2, since 2 belongs to -3 will be 9

Finally 1/10^9.
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by azarkin » Wed Jul 16, 2014 8:40 am
Got it thnx, was confusing it
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by GMATinsight » Wed Jul 16, 2014 10:17 am
Please check the following rules for better understanding

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