Question

If x+ 1/x= 5 . Then find the value of x3+1/x3. Please answer this. I will rate you brainist. explain with steps​

Answer 1

Given:

x + 1/x = 5

To find:

Find the value of x³ + 1/x³ = ?

Formula used:

( a + b )³ = a³ + b³ + 3 ( a + b )

Solution:

x + 1/x = 5

Cubing both sides ,we get

( x + 1/x )³ = (5)³

x³ + 1/x³ + 3 ( x + 1/x ) = 125

x³ + 1/x³ + 3 × 5 = 125

x³ + 1/x³ = 125 - 15

x³ + 1/x³ = 120

Hence, the value of x³ + 1/x³ is 120 .