If find the value of
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 301.
a3 + b3 = (a + b)3 – 3ab(a + b)
Given, x + 2/x = 7
x3 + (2/x)3 = (x + 2/x)3 – 3x(2/x)(x + 2/x)
⇒ x3 + 8/x3 = 73 – 3 × 2 × 7
⇒ x3 + 8/x3 = 343 – 42 = 301