1. **State the problem:** Solve the inequality $$x(x+2) - 3(2x - 1) \leq 2^2$$.
2. **Rewrite the inequality:** Expand and simplify the left side.
$$x(x+2) - 3(2x - 1) \leq 4$$
$$x^2 + 2x - 6x + 3 \leq 4$$
3. **Combine like terms:**
$$x^2 - 4x + 3 \leq 4$$
4. **Bring all terms to one side:**
$$x^2 - 4x + 3 - 4 \leq 0$$
$$x^2 - 4x - 1 \leq 0$$
5. **Solve the quadratic inequality:**
First, find the roots of the quadratic equation $$x^2 - 4x - 1 = 0$$ using the quadratic formula:
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$ where $$a=1$$, $$b=-4$$, and $$c=-1$$.
Calculate the discriminant:
$$\Delta = (-4)^2 - 4(1)(-1) = 16 + 4 = 20$$
Calculate the roots:
$$x = \frac{4 \pm \sqrt{20}}{2} = \frac{4 \pm 2\sqrt{5}}{2} = 2 \pm \sqrt{5}$$
6. **Determine the solution set:**
Since the parabola opens upwards (coefficient of $$x^2$$ is positive), the inequality $$x^2 - 4x - 1 \leq 0$$ holds between the roots.
Therefore, the solution is:
$$2 - \sqrt{5} \leq x \leq 2 + \sqrt{5}$$
**Final answer:**
$$\boxed{2 - \sqrt{5} \leq x \leq 2 + \sqrt{5}}$$
Quadratic Inequality 4E7Bea
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.