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    If x2−3x+1=0x^2-3x+1=0x2−3x+1=0​, then the value of x2+x+(1x)+(1x2)x^2+x+(\frac{1}{x})+(\frac{1}{x^2})x2+x+(x1​)+(x21​)​ is:
    Question

    If x23x+1=0x^2-3x+1=0​, then the value of x2+x+(1x)+(1x2)x^2+x+(\frac{1}{x})+(\frac{1}{x^2})​ is:

    A.

    2

    B.

    10

    C.

    6

    D.

    8

    Correct option is B

    Given:

    x23x+1=0x^2 - 3x + 1 = 0

    ​​x2+x+1x+1x2x^2 + x + \frac{1}{x} + \frac{1}{x^2} = ?

    Formula Used:
    If x +1x=+ \frac{1}{x} = a, then

    x2+1x2=a22x^2 + \frac{1}{x^2} = a^2 - 2

    Solution:
    From the equation:

    x2+1=3xx^2 + 1 = 3x​​

    x2+1x=3\frac{x^2 + 1}{x} = 3​​

    x+1x=3x + \frac{1}{x} = 3​​

    So,

    x2+1x2=322=92=7x^2 + \frac{1}{x^2} = 3^2 - 2 = 9 - 2 = 7​​

    Now add both:

    x2+x+1x+1x2=x+1x+x2+1x2=3+7=10x^2 + x + \frac{1}{x} + \frac{1}{x^2}= x + \frac{1}{x} +x^2 + \frac{1}{x^2} = 3 + 7 = 10

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