What is the value ?

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What is the value ?

by goelmohit2002 » Tue Jul 21, 2009 11:16 am
Hi All,

Can some one please tell what is the following equation equals:

-2^4

is it equal to
a) (-2)^4 = 16 or
b) -(2^4) = -16

As far as I know that in GMAT -x^4 = -(x^4)....

But here in the above question, should we treat sign and number as separate as in option b above....or together i.e. option A above....
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by Ian Stewart » Tue Jul 21, 2009 11:50 am
If there are no parentheses at all, you always need to evaluate exponents before multiplication (and when you see a negative sign, that really is a multiplication by -1). So with no bracketing, -2^4 is equal to -(2^4), or -16. It is not equal to (-2)^4, which is 16.
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by goelmohit2002 » Tue Jul 21, 2009 12:03 pm
Thanks a lot Ian !!