1. **State the problem:** Solve the equation $$16x + 16 = x^2 + 2x + 1$$.
2. **Rewrite the equation:** Notice that $$x^2 + 2x + 1 = (x + 1)^2$$, so the equation becomes:
$$16x + 16 = (x + 1)^2$$
3. **Bring all terms to one side:**
$$0 = (x + 1)^2 - 16x - 16$$
Expand the square:
$$0 = x^2 + 2x + 1 - 16x - 16$$
Simplify:
$$0 = x^2 - 14x - 15$$
4. **Solve the quadratic equation:**
Use the quadratic formula:
$$x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}$$
where $$a=1$$, $$b=-14$$, and $$c=-15$$.
Calculate the discriminant:
$$\Delta = (-14)^2 - 4 \times 1 \times (-15) = 196 + 60 = 256$$
Calculate the roots:
$$x = \frac{-(-14) \pm \sqrt{256}}{2 \times 1} = \frac{14 \pm 16}{2}$$
5. **Find the two solutions:**
- For the plus sign:
$$x = \frac{14 + 16}{2} = \frac{30}{2} = 15$$
- For the minus sign:
$$x = \frac{14 - 16}{2} = \frac{-2}{2} = -1$$
6. **Check for extraneous solutions:**
Substitute $$x = -1$$ back into the original equation:
$$16(-1) + 16 = -16 + 16 = 0$$
$$(-1)^2 + 2(-1) + 1 = 1 - 2 + 1 = 0$$
Both sides equal 0, so $$x = -1$$ is valid.
Substitute $$x = 15$$:
$$16(15) + 16 = 240 + 16 = 256$$
$$(15)^2 + 2(15) + 1 = 225 + 30 + 1 = 256$$
Both sides equal 256, so $$x = 15$$ is valid.
**Final answer:** $$x = -1$$ or $$x = 15$$.
Quadratic Equation 29E439
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