1. **State the problem:** Solve the inequality $$-2x^2 + 12x + 52 \leq -2$$ algebraically.
2. **Rewrite the inequality:** Move all terms to one side to set the inequality to zero:
$$-2x^2 + 12x + 52 + 2 \leq 0$$
which simplifies to
$$-2x^2 + 12x + 54 \leq 0$$
3. **Divide the entire inequality by -2** to simplify, remembering to reverse the inequality sign because we divide by a negative number:
$$\cancel{-2}x^2 \cancel{/\cancel{-2}} - \frac{12x}{-2} - \frac{54}{-2} \geq 0$$
which simplifies to
$$x^2 - 6x - 27 \geq 0$$
4. **Solve the quadratic equation** $$x^2 - 6x - 27 = 0$$ to find critical points.
Use the quadratic formula:
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $$a=1$$, $$b=-6$$, $$c=-27$$.
Calculate the discriminant:
$$\Delta = (-6)^2 - 4(1)(-27) = 36 + 108 = 144$$
Calculate roots:
$$x = \frac{6 \pm \sqrt{144}}{2} = \frac{6 \pm 12}{2}$$
So,
$$x_1 = \frac{6 - 12}{2} = \frac{-6}{2} = -3$$
$$x_2 = \frac{6 + 12}{2} = \frac{18}{2} = 9$$
5. **Analyze the inequality** $$x^2 - 6x - 27 \geq 0$$.
Since the parabola opens upward (coefficient of $$x^2$$ is positive), the expression is:
- Greater than or equal to zero outside the roots
- Less than zero between the roots
6. **Write the solution:**
$$x \leq -3$$ or $$x \geq 9$$
**Final answer:** $$\boxed{x \leq -3 \text{ or } x \geq 9}$$
Quadratic Inequality E94F02
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