Question

    If 2a - 3b = 8 and ab = 7, then find the value of 2a +

    3b.
    A 2√58 Correct Answer Incorrect Answer
    B 3√58 Correct Answer Incorrect Answer
    C 5√58 Correct Answer Incorrect Answer
    D 2√66 Correct Answer Incorrect Answer

    Solution

    Squaring both the sides
    64 = 4a² + 9b² - 12(7)
    64 + 84 = 4a² + 9b²
    148 = 4a² + 9b²
    (2a + 3b)² = 148 + 84 = 232
    (2a + 3b) = 2√58

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