1. **State the problem:** Solve the quadratic equation $$5x^2 + 10x - 45 = 0$$ by completing the square.
2. **Divide the entire equation by 5** to simplify the coefficient of $$x^2$$ to 1:
$$\frac{5x^2}{5} + \frac{10x}{5} - \frac{45}{5} = \frac{0}{5}$$
which simplifies to
$$\cancel{5}x^2 + \cancel{2}x - \cancel{9} = 0$$
actually, correctly:
$$x^2 + 2x - 9 = 0$$
3. **Move the constant term to the right side:**
$$x^2 + 2x = 9$$
4. **Complete the square:** Take half of the coefficient of $$x$$, which is $$2$$, half is $$1$$, then square it: $$1^2 = 1$$.
Add this to both sides:
$$x^2 + 2x + 1 = 9 + 1$$
5. **Rewrite the left side as a perfect square:**
$$(x + 1)^2 = 10$$
6. **Take the square root of both sides:**
$$x + 1 = \pm \sqrt{10}$$
7. **Solve for $$x$$:**
$$x = -1 \pm \sqrt{10}$$
**Final answer:**
$$x = -1 + \sqrt{10} \quad \text{or} \quad x = -1 - \sqrt{10}$$
Completing Square 85B52A
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