Question

URGENTE ! Simplifique e calcule o valor das expressões : A) 3! 5! / 5!7 B) 15!/9! C) 9! 8!/ 7! 6! D) 21!/18

Answer 1

$a) \frac{3!5!}{5!7} = \frac{3!}{7} = \frac{3.2.1}{7} = \frac{6}{7} \\ \\b) \frac{15!}{9!} = \frac{15.14.13.12.11.10.9!}{9!} = 15.14.13.12.11.10 = 3603600 \\ \\ c) \frac{9!8!}{7!6!} = \frac{9.8.7!.8.7.6!}{7!6!} =9.8.8.7=4032 \\ \\ d) \frac{21!}{18} =21.20.19.18.17!=21.20.19.17!=7980.17!$

d) Se for 21!/18! = 21.20.19 = 8379