ГДЗ по алгебре и начала математического анализа 10 класс Алимов Задание 1099

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\[1)\ \frac{A_{7}^{4}}{P_{5}} = \frac{7!}{(7 - 4)!} \bullet \frac{1}{5!} =\]

\[= \frac{7 \bullet 6 \bullet 5!}{3!} \bullet \frac{1}{5!} = \frac{7 \bullet 6}{3 \bullet 2} = 7\]

\[2)\ \frac{A_{6}^{3}}{P_{4}} = \frac{6!}{(6 - 3)!} \bullet \frac{1}{4!} =\]

\[= \frac{6 \bullet 5 \bullet 4!}{3!} \bullet \frac{1}{4!} = \frac{6 \bullet 5}{3 \bullet 2} = 5\]

\[= \left( 11 \bullet 3 - \frac{21}{5} \right) \bullet \frac{1}{3} =\]

\[= \frac{165 - 21}{5} \bullet \frac{1}{3} = \frac{144}{15} = \frac{48}{5} =\]

\[= 9,6\]