If a - \(\frac{1}{a - 5}\) = 11
Then find , (a - 5)3 - \(\frac{1}{(a - 5)^3}\)
Answer & explanation
Correct answer: option 3
Given = a - \(\frac{1}{a - 5}\) = 11
By subtracting 5 on both sides we get,
(a - 5) - \(\frac{1}{a - 5}\) = 11 - 5 = 6
(a - 5)3 - \(\frac{1}{(a - 5)^3}\) = 63 + 3 × 6 = 234
Note - if x - \(\frac{1}{x}\) = a
then x3 - \(\frac{1}{x^3}\) = a3 + 3a