exponent question

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exponent question

by scoutkb » Mon Mar 26, 2007 3:52 pm
Hi,

This question is from a MGMAT online test. The answer is A, but i just didnt understand the explination. Can anyone help?


5^5 + 5^5 +5^5 + 5^5 + 5^5 = ?

a) 5^6

b) 25^5

C) 15525

d) 5^25

e) 25^25

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by maxim730 » Mon Mar 26, 2007 4:16 pm
exponent properties:

x^a + x^a = 2(x^a)

so

5^5 + 5^5 + 5^5 + 5^5 + 5^5 =

5(5^5) = 5^1(5^5)

=5^6

another way to look at it is:

x + x = 2(x)

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by Cybermusings » Tue Mar 27, 2007 3:56 am
It's pretty simple...If written is an exponential form it equals

= 5^5 + 5^5 + 5^5 + 5^5 + 5^5

= 5 times 5^5

= 5^6

Hope this helps

Cheers
Last edited by Cybermusings on Tue Mar 27, 2007 10:42 am, edited 1 time in total.

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by scoutkb » Tue Mar 27, 2007 3:57 am
Awsome...thanks for the help.