Question

simplifique as frações

a) 8! 9!
7! 8!

b) n!
(n+3)!

c) n!
(n-2)!

Answer 1

a) 8!9!/7!8!

9!/7!

9.8.7!/7!

9x8 = 72
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b) n!/(n+3)

n!/(n+3).(n+2).(n+1).n!

1/(n+3).(n+2).(n+1)

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C) n!/(n-2)!

n.(n-1).(n-2)!/(n-2)!

n.(n-1)