Question

If x+1/x = 5 find the value of x^3 +1/x^3. pls solve​

Answer 1

1) solve x+1/x = 5

`(x + 1)/(x) = 5`

`x + 1 = 5x`

`x - 5x = - 1`

`- 4x = - 1`

`x = ( -1)/( - 4)`

`x = (1)/(4)`

2) solve x³+1/x³

`x {}^(3) + \frac{1}{x {}^(3) }`

substitute x = 1/4 into the expression

`( (1)/(4) ) {}^(3) + \frac{1}{( (1)/(4)) {}^(3) }`

`(1)/(64) + (1)/( (1)/(64) )`

`(1)/(64) + (64 * 1)/(1)`

`(1)/(64) + 64`

`(4097)/(64) \: or \: 64.02`