Multiple choice

Find the roots of given equation. x2 + 4x - 21 = 0

  1. 3, -7

  2. 4, -2

  3. -2, -4

  4. -3, -7
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A Correct answer
Explanation

x^2 + 4x - 21 = 0. Factoring: (x + 7)(x - 3) = 0. The roots are x = -7 and x = 3.

AI explanation

To find the roots of the quadratic equation x^2 + 4x - 21 = 0, we factor the quadratic expression by finding two numbers that multiply to -21 and add to 4. These numbers are 7 and -3, so the equation becomes (x + 7)(x - 3) = 0. Setting each factor to zero gives x = -7 and x = 3, so the roots are 3 and -7.

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