x + (2/x) = 3 হলে x3 + 8/x3 এর মান কত?

x + (2/x) = 3 হলে x³ + 8/x³ এর মান কত?

A 1

B 8

C 9

D 16

Solution

Correct Answer: Option C

= x³ + 8/x³

= x³ + (2/x)³

= {x+ (2/x)}³ - 3.x.2/x {x+(2/x)}

= 3³ - 3.2.3

= 27 - 18

= 9