log4 24 - log4 9 · log9 13 · log13 6 = log4 24 - log4 9 · 1 / log13 9 · log13 6 = log4 24 - log4 9 · log13 6 / log13 9 = log4 24 - log4 9 · log13 ( 6 / 9 ) = log4 24 - log4 9 · log13 ( 2 / 3 ) = log4 24 - log( 2 ^ 2 ) ( 3 ^ 2 ) · log13 ( 2 / 3 ) = log4 24 - 2 / 2 * log2 3 · log13 ( 2 / 3 ) = log4 ( 4 * 6 ) - log2 3 · log13 ( 2 / 3 ) = log4 4 + log 4 6 - log2 3 · log13 ( 2 / 3 ) = 1 + log( 2 ^ 2 ) 3 ^ 2 - log2 3 · log13 ( 2 / 3 ) = 1 + log2 3 - log2 3 · log13 ( 2 / 3 ) = 1 + log2 3 * ( 1 - log13 ( 2 / 3 ) ) = 1 + 1.585 * ( 1 - 0.27 ) = 1 + 1.585 * 0.73 = 1 + 1.15705 = 2.15705.