Найдите значение выражения:

а) 8! / 6! ⋅ 2!

б) 12! / 9! ⋅ 3!

в) 7! ⋅ 5! / 8! ⋅ 4!

Решение:

а) 8! / 6! ⋅ 2! = 6! ⋅ 7 ⋅ 8 / 6! ⋅ 1 ⋅ 2 = 7 ⋅ 4 = 28

б) 12! / 9! ⋅ 3! = 9! ⋅ 10 ⋅ 11 ⋅ 12 / 9! ⋅ 1 ⋅ 2 ⋅ 3 = 10 ⋅ 11 ⋅ 2 = 220

в) 7! ⋅ 5! / 8! ⋅ 4! = 7! ⋅ 4! ⋅ 5 / 7! ⋅ 8 ⋅ 4! = 5/8

Источник : Учебник по Алгебре 9 класса авторов Ю.Н. Макарычев, Н.Г. Миндюк, К.И. Нешков, С.Б. Суворова, 2014г.