If a + \(\frac{1}{a + 7}\) = 3 Then find , (a + 7)3 + \(\frac{1}{(a + 7)^3}\)

1100 1000 970 960

970

Given = a + \(\frac{1}{a + 7}\) = 3 By adding 7 on both sides we get, (a + 7) + \(\frac{1}{a + 7}\) = 3 + 7 = 10 (a + 7)3 + \(\frac{1}{(a + 7)^3}\) = 103 - 3 × 10 = 970   Note - if x +  \(\frac{1}{x}\) = a then x3 + \(\frac{1}{x^3}\) =  a3 - 3a