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Question
if `1/(6!) + 1/(7!) = x/(8!)`, find x
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Solution
`1/(6!) + 1/(7!) = x/(8!)`
⇒ `1/(6!) + 1/(7 xx 6!) = x/(8 xx 7 xx 6!)`
⇒ `1/(6!) (1 + 1/7) = x/(8 xx 7 xx 6!)`
⇒ `1 + 1/7 = x/(8 xx 7)`
⇒ `8/7 = x/(8 xx 7)`
⇒ x = `(8 xx 8 xx 7)/7`
∴ x = 64
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