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Question
Find n, if `1/("n"!) = 1/(4!) - 4/(5!)`
Solution
`1/("n"!) = 1/(4!) - 4/(5!)`
∴ `1/("n"!) = 1/(4!) - 4/(5!)`
∴ `1/("n"!) = 5/(5xx4!)- 4/(5!)`
∴ `1/("n"!) = 5/(5!)-4/(5!)`
∴ `1/("n"!) = 1/(5!)`
∴ n! = 5!
∴ n = 5
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