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2 Exponent Equations

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Guest
 Post subject: 2 Exponent Equations
 Post Posted: Sat Aug 30, 2008 10:02 pm 
Hi,
Could you please help me to solve these problems:
1) 5^21 * 4^11=2*10^n
What is n?

2) 2^x - 2^x-2 = 3* 12^13
What is X?

Thanks!
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Guest
 Post subject:
 Post Posted: Mon Sep 01, 2008 2:35 pm 
Hi, I'm answering one of my own questions. All turned out to be very simple:

5^21 * 4^11 = 2 * 10^n
5^21 * (2^2)^11 = 2 * (5*2)^n
5^21 * 2^22 = 2 * 5^n * 2^n
5^21 * 2^22 = 2^n=1 * 5
21=n
22 = n+1
n=21
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RonPurewal
 Post subject:
 Post Posted: Mon Sep 15, 2008 6:42 am 
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ManhattanGMAT Staff


Posts: 7146
#2 is here.

DO NOT post more than one problem in a thread. if you do, we'll usually just delete the thread.
see the forum rules.
thanks.
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