same base

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same base

by kanha81 » Mon Apr 20, 2009 7:43 am
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by bluementor » Mon Apr 20, 2009 7:57 am
2^((x+y)^2) / 2^((x-y)^2)

=2^(x^2 + 2xy + y^2) / 2^(x^2 - 2xy + y^2)
=2^(x^2 + 2xy + y^2 - x^2 + 2xy - y^2)
=2^(4xy)

Since xy = 1

2^(4xy) = 2^4 = 16.

Choose D.

-BM-