Question

if x+1/x = 8 then find x cube+1/x cube

Answer 1

Hi ,

x + 1/x = 8 ----( 1 )

x³ + 1/x³ = ( x + 1/x )³ - 3 ( x + 1/x )

= 8³ - 3 × 8

= 8 ( 8² - 3 )

= 8 ( 64 - 3 )

= 8 × 61


= 488

I hope this helps you.

: )

Answer 2

Answer:

[(x+1/x)^3 -3(x+1/x)]

8^3-3×8

8(8^2-3)

8(64-3)

8×61

488