Question

If x- 1/x=5, find the value of x³ - 1/x³

Answer 1

HERE'S YOUR ANSWER

HOPE YOU LIKE IT......

AND PLEASE MARK AS BRAINALIST ANSWER

PLEASE PLEASE PLEASE.........

Answer 2

Given : x - 1/x=5

 

To find : value of x³ - 1/x³

 

Solution :  

We have  x - 1/x = 5 ……..(1)

On cubing eq 1 both sides,  

(x - 1/x)³ = (5)³

By using the identity, (a - b)³ = a³ - b³ - 3ab(a - b)  

x³ - 1/x³ - 3 x × 1/x (x - 1/x) = 125

x³ - 1/x³ - 3 (x - 1/x) = 125

x³ - 1/x³ - 3 (5) = 125

x³ - 1/x³ - 15 = 125

x³ - 1/x³  = 125 + 15

x³ - 1/x³ = 140

Hence the value of  x³ - 1/x³  is 140 .

HOPE THIS ANSWER WILL HELP YOU…..

 

Similar questions :

If x = 2+ √3, find the value of x³ + 1/x³

https://brainly.in/question/15897358

 

If x- 1/x= 7, find the value of x³ - 1/x³

https://brainly.in/question/15897613