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exponents prob..

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Re: exponents prob..

by sureshbala » Mon Feb 09, 2009 2:36 pm
willbeatthegmat wrote:If (2^2x+1)(3^2y-1) = 8^x .27^y, then x+y=?

-3
-1
0
1
3


OA C
Friend, your question has to be [2^(2x+1)][3^(2y-1)] = 8^x . 27^y

We can write this as [2^(2x+1)][3^(2y-1)] = 2^3x . 3^3y

Thus 2x+1 = 3x and 2y-1 = 3y

Hence x = 1 and y = -1.

Thus x+y = 0
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