GMAT Prep - exponents

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by sethids » Mon Sep 01, 2008 5:03 pm
The given expression can be re-written as:

(1001 + 999) (1001 - 999)/(101 + 99) (101 - 99)

= 2000*2/200*2
= 10
Last edited by sethids on Mon Sep 01, 2008 5:10 pm, edited 1 time in total.

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by sushilmore » Mon Sep 01, 2008 5:05 pm
1001^2 - 999^2)/ 101^2 - 99^2

= (1001 -999)(1001+999)/(101-99)(101+99)

= 2*2000 / 2 * 200

= 10

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by nervesofsteel » Tue Sep 02, 2008 12:21 am
yes A is the answer

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by aj5105 » Thu May 07, 2009 9:17 pm
Using the formula (a + b)(a - b) = a^2 - b^2, we get 10 (A)