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Exponents - Which is greatest?

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Exponents - Which is greatest?

by adi » Fri Mar 14, 2008 7:46 pm
Of the following, which is greatest?

A) (1/5) ^ -2
B) (1/3) ^ -2
C) 3^-2
D) 5^-2
E) 2^3

A is the right answer. I thought so too but wasn't exactly sure on the rules. Would you change A to 5^2? If so, what are the exact rules for this one. I know that 3^-2 is (1/3)^2.... would you flip A using the same rule?
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by simplyjat » Fri Mar 14, 2008 10:35 pm
There is no rule actually, only the definition of negative powers. Negative power n of a number x means 1 divided by x, n times...
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by smushkas » Sat Mar 15, 2008 2:43 am
Hey there,

You are right. See, it is a fraction and you have to flip it, too.
(1/5)^-2 = [1 / (1/5)^2] = [1 / (5/1)^2] = [1* 25/1 ] = 25

Hope it is clear!
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Re: Exponents - Which is greatest?

by xeqtr » Sat Mar 15, 2008 11:30 am
Yes you can flip A using the same rule;
since 1/5 = 5^-1, you end up with (5^-1)^-2 => -1x-2 = 2 =>> 5^2. hope it makes more sense.
adi wrote:Of the following, which is greatest?

A) (1/5) ^ -2
B) (1/3) ^ -2
C) 3^-2
D) 5^-2
E) 2^3

A is the right answer. I thought so too but wasn't exactly sure on the rules. Would you change A to 5^2? If so, what are the exact rules for this one. I know that 3^-2 is (1/3)^2.... would you flip A using the same rule?
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