If x - 3/x = 6, x ≠ 0, then the value of is:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 90
x - 3/x = 6..........(1)
On cubing both sides we get,
x3 - 27/x3 - 3 × x × 3/x(x - 3/x) = 216
x3 - 27/x3 - 54 = 216
x3 - 27/x3 = 270..............(2)
,
On dividing the numerator and denominator by x we get,
= (x3 - 27/x3)/(x - 3/x - 3)
= 270/(6 - 3)
= 270/3 = 90.