Ответ был таков:как там... а ответ буква Б
Цена билетов не изменилась. Допустим цена была 8, поднимаем на 25% = 10, понижаем на 20% = 8. И так будет с любой ценой. Дело в том, что 25% - это 1/4, а 20% - 1/5, если к какому либо числу прибавить 1/4 от него, а потом отнять 1/5 от полученного числа, то получится исходное число. Поэтому цена не изменится.
<span>1/2 log7 36 - log7 14 - 3log7 ∛21 = <span>1/2 log7 6² - <span>log7 14 - log7 (∛21)³ = </span></span></span>
<span><span><span>= 1/2 · 2· <span><span>log7 6 - <span><span><span>log7 14 - log7 21 = <span><span><span><span><span>log7 6 - <span><span><span>log7 14 - log7 21</span></span></span></span></span></span></span></span> = </span></span></span></span></span></span></span></span>
<span><span><span>= <span><span><span><span><span><span><span><span><span><span><span><span><span>log7 (6:14:21) = <span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span>lo</span></span></span></span></span></span></span></span>g7 (1/49) =<span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span> <span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span>lo</span></span></span></span></span></span></span></span>g7 (7⁻²) = -2<span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span><span>lo</span></span></span></span></span></span></span></span>g7</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span> 7 = -2·1 = -2</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
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8+6=14- это столько птенцов.
14+14=28.
ответ-28 пеликанов в вольере