1. **State the problem:** Solve the quadratic equation $$x^2 + 2x - 80 = 0$$ by factoring.
2. **Recall the factoring method:** To factor a quadratic equation of the form $$ax^2 + bx + c = 0$$, we look for two numbers that multiply to $$ac$$ and add to $$b$$.
3. **Apply to our equation:** Here, $$a=1$$, $$b=2$$, and $$c=-80$$.
We need two numbers that multiply to $$1 \times (-80) = -80$$ and add to $$2$$.
4. **Find the numbers:** The pair $$10$$ and $$-8$$ works because $$10 \times (-8) = -80$$ and $$10 + (-8) = 2$$.
5. **Rewrite the middle term:**
$$x^2 + 10x - 8x - 80 = 0$$
6. **Group terms:**
$$(x^2 + 10x) + (-8x - 80) = 0$$
7. **Factor each group:**
$$x(x + 10) - 8(x + 10) = 0$$
8. **Factor out the common binomial:**
$$(x - 8)(x + 10) = 0$$
9. **Set each factor equal to zero:**
$$x - 8 = 0 \quad \Rightarrow \quad x = 8$$
$$x + 10 = 0 \quad \Rightarrow \quad x = -10$$
**Final answer:** $$x = 8$$ or $$x = -10$$
Solve Quadratic 5C0213
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