Multiple choice

Using the method of factorisation, find which of the following is/are the root(s) of the quadratic equation: (2x + 3)2 = 81

  1. Only 3

  2. 3 and - 6

  3. Only - 3
    • 3 and 6

  5. NA
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B Correct answer
Explanation

Taking the square root of both sides of the equation (2x + 3)^2 = 81 gives 2x + 3 = 9 or 2x + 3 = -9. Solving the first equation yields x = 3, and solving the second equation yields x = -6. Thus, the roots of the quadratic equation are 3 and -6.

AI explanation

Take the square root of both sides of the equation (2x + 3) squared equals 81 to get two linear equations: 2x + 3 equals 9 and 2x + 3 equals -9. Solving the first equation gives 2x equals 6, which means x equals 3. Solving the second equation gives 2x equals -12, resulting in x equals -6. The roots of the equation are 3 and -6.

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