Предмет: Алгебра, автор: BlueSky10

а) A frac{4}{12} - A frac{4}{11}  /   A frac{3}{10} <br />
б) A  frac{4}{15} + A  frac{5}{14}  /  Afrac{3}{15} <br />
в) A  frac{3}{13} /   A frac{3}{15} - A frac{3}{14}

Ответы

Автор ответа: eugeke
0
A^4_{12}-A^4_{11}:A^3_{10}=11880-7920:720=11880-11=11869\\
A^4_{12}= frac{12!}{(12-4)!}= frac{12!}{8!}= frac{1cdot2cdot3cdot4cdot5cdot6cdot7cdot8cdot9cdot10cdot11cdot12}{1cdot2cdot3cdot4cdot5cdot6cdot7cdot8}=9cdot10cdot11cdot12=11880\\
A^4_{11}= frac{11!}{(11-4)!}=  frac{11!}{7!}=7920\\
A^3_{10}= frac{10!}{(10-3)!}= frac{10!}{7!}=720


A^4_{15}+A^5_{14}:A^3_{15}=32760+240240:2730=32760+88=32848\\ A^4_{15}= frac{15!}{(15-4)!}= frac{15!}{11!}=32760\\ A^5_{14}= frac{14!}{(14-5)!}= frac{14!}{9!}=240240\\ A^3_{15}= frac{15!}{(15-3)!}= frac{15!}{12!} =2730


A^3_{13}:A^3_{15}-A^3_{14}=1716:2730-2184=\\ A^3_{13}= frac{13!}{10!}=1716 \\ A^3_{15}= frac{15!}{12!}= 2730\\ A^3_{14}= frac{14!}{11!}=2184



Автор ответа: BlueSky10
0
а почему непонятным шрифтом написано*
Автор ответа: BlueSky10
0
аааа все
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