Question

x3+1/x3=110,thenx+1/x

Answer 1

what is your question x cube or x3 and what to do
find the value of x +1/x

Answer 2

Hi ,

it is given that ,

x³ + 1/x³ = 110 ---( 1 )

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we know the algebraic identity ,

a³ + b³ + 3ab( a + b ) = ( a + b )³

Or

a³ + b³ = ( a + b )³ - 3ab( a + b )

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( x + 1/x )³ - 3 × x × 1/x ( x + 1/x ) = 110

( x + 1/x )³ - 3( x + 1/x ) = 110

Let ( x + 1/x ) = m---( 2 )

m³ - 3m = 110 ---( 3 )

if m = 5 ,

5³ - 3 × 5 = 110

125 - 15 = 110

110 = 110 ( True )

therefore ,

m = 5 root of equation ( 3 ) .

from ( 2 ) ,

x + 1/x = 5

I hope this helps you.

: )