if x+1 upon x=7 then find the value of x³+1 upon x³
Answers
Answered by
2
Heya
x + 1/x = 7
( x + 1/x ) = 7
x³ + 1/x³ = ( x + 1/x )³ -3 ( x + 1/x )
=>
x³ + 1/x³ = ( 7 )³ - 3 ( 7 )
=>
x³ + 1/x³ = 343 - 21
=>
x³ + 1/x³ = 322
x + 1/x = 7
( x + 1/x ) = 7
x³ + 1/x³ = ( x + 1/x )³ -3 ( x + 1/x )
=>
x³ + 1/x³ = ( 7 )³ - 3 ( 7 )
=>
x³ + 1/x³ = 343 - 21
=>
x³ + 1/x³ = 322
Answered by
0
x+1\x=7
x^3+1\x^3=(x+1/x){x^2-1/x ×x+(1/x)^2}
=7{(x+1/x)^2-3 1/x ×x}
=7{(7)^2-3}
=7×46
=322 Ans.
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