Question

    If x + 1/x = 3, find the value of x³ +

    1/x³.
    A 18 Correct Answer Incorrect Answer
    B 19 Correct Answer Incorrect Answer
    C 21 Correct Answer Incorrect Answer
    D 27 Correct Answer Incorrect Answer

    Solution

    Using the identity: x³ + 1/x³ = (x + 1/x)³ - 3(x + 1/x). Substituting x + 1/x = 3: x³ + 1/x³ = 3³ - 3(3). x³ + 1/x³ = 27 - 9 = 18. Correct option: a) 18

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