100 ^ N = ( 25 * 4 ) ^ N = ( 5 ^ 2N ) * ( 2 ^ 2N )
( 5 ^ 2N - 1 ) * ( 4 ^ N - 2 ) = ( 5 ^ 2N - 1 ) * ( 2 ^ 2N - 4 )
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[ ( 5 ^ 2N ) * ( 2 ^ 2N ) ] / [ ( 5 ^ 2N - 1 ) * ( 2 ^ 2N - 4 ) =
= 5 ^ ( 2N - 2N + 1 ) * 2 ^ ( 2N - 2N + 4 ) = ( 5 ^ 1 ) * ( 2 ^ 4 ) =
= 5 * 16 = 80
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ОТВЕТ 80