please give right answer and please give only answer.
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solve using the below method mention
Step-by-step explanation:
x^2 + x - 1 = 0 ;
x^2 + x = 1 ;
x(x+1) = 1;
It tells that x is a non zero quantity, because if x=0, above equation(question) does not satisfy.
If x != 0 ;
we can divide mentioned equation by x.
(x^2 + x - 1)/x = 0/x;
x + 1 - 1/x = 0;
x - 1/x = -1;
Now square both side:
x^2 - 2.x.(1/x) + 1/x^2 = 1;
x^2 - 2 + 1/x^2 = 1;
x^2 + 1/x^2 = 3;
Again square both side:
x^4 +2.x^2.(1/x^2) +1/x^4 = 9;
x^4 + 2 + 1/x^4 = 9;
x^4 + 1/x^4 = 7;
Ans = 7.
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