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Solve \(x^2 + 6x - 12 = 0\) using the quadratic formula.

First, identify the value of \(a\), \(b\) and \(c\). In this example, \(a = 1\), \(b = 6\) and \(c = -12\).

\(x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}\)

\(x = \frac{(- 6) \pm \sqrt{6^2 - 4 \times 1 \times (-12)}}{2 \times 1}\)

\(x = \frac{(-6) \pm \sqrt{36 + 48}}{2}\)

\( x = \frac{(-6) \pm \sqrt{84}}{2}\)

\(x = \frac{(-6) \pm \sqrt{84}}{2}\)

The first solution is \(x = \frac{(-6) + \sqrt{84}}{2} = 1.58\) (2 dp).

The second solution is \(x = \frac{(-6) - \sqrt{84}}{2} = -7.58\) (2 dp).