Question

If x = 9-4√5 , find the value of x³-1/x³​

Answer 1

x=9-4$\sqrt5$

=> $x^{3$-1/$x^{3}$

=> 9-4$\sqrt{5}$ - 1 / 9-4

=> 9−4√5− 1  / 9−4√5

=> −8√5

HOPE IT HELPS!

PLEASE MARK AS BRAINLIEST !!!

Answer 2

Answer:

Answer

We have,

x=9−4

5

x

1

=9+4

5

Therefore,

x−

x

1

=−8

5

x+

x

1

=18

Since,

x

3

−

x

3

1

=(x−

x

1

)(x

2

+

x

2

1

+1)

=(−8

5

)

⎣

⎢

⎡

(x+

x

1

)

2

−1

⎦

⎥

⎤

=(−8

5

)[323]

=−2584

5

Hence, this is the answer