1. **State the problem:** Solve the quadratic equation $x^2 + 2x - 5 = 0$ using the discriminant formula $D = b^2 - 4ac$.
2. **Identify coefficients:** Here, $a = 1$, $b = 2$, and $c = -5$.
3. **Calculate the discriminant:**
$$D = b^2 - 4ac = 2^2 - 4 \times 1 \times (-5) = 4 + 20 = 24$$
4. **Interpret the discriminant:** Since $D > 0$, there are two distinct real roots.
5. **Use the quadratic formula:**
$$x = \frac{-b \pm \sqrt{D}}{2a} = \frac{-2 \pm \sqrt{24}}{2 \times 1}$$
6. **Simplify the square root:**
$$\sqrt{24} = \sqrt{4 \times 6} = 2\sqrt{6}$$
7. **Substitute back:**
$$x = \frac{-2 \pm 2\sqrt{6}}{2}$$
8. **Cancel common factor 2:**
$$x = \frac{\cancel{2}(-1 \pm \sqrt{6})}{\cancel{2}} = -1 \pm \sqrt{6}$$
9. **Final solutions:**
$$x_1 = -1 + \sqrt{6}, \quad x_2 = -1 - \sqrt{6}$$
These are the two real roots of the quadratic equation.
Quadratic Discriminant 42B290
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