1. **State the problem:** Solve the quadratic equation $$3x^2 - 20x - 13 = -6$$ by factoring.
2. **Rewrite the equation:** Move all terms to one side to set the equation equal to zero:
$$3x^2 - 20x - 13 + 6 = 0$$
$$3x^2 - 20x - 7 = 0$$
3. **Identify coefficients:** Here, $$a = 3$$, $$b = -20$$, and $$c = -7$$.
4. **Multiply $$a$$ and $$c$$:**
$$3 \times (-7) = -21$$
5. **Find two numbers that multiply to $$-21$$ and add to $$b = -20$$:**
These numbers are $$-21$$ and $$1$$ because $$-21 \times 1 = -21$$ and $$-21 + 1 = -20$$.
6. **Rewrite the middle term using these numbers:**
$$3x^2 - 21x + x - 7 = 0$$
7. **Group terms:**
$$(3x^2 - 21x) + (x - 7) = 0$$
8. **Factor each group:**
$$3x(x - 7) + 1(x - 7) = 0$$
9. **Factor out the common binomial:**
$$(3x + 1)(x - 7) = 0$$
10. **Set each factor equal to zero and solve for $$x$$:**
$$3x + 1 = 0 \Rightarrow 3x = -1 \Rightarrow x = \frac{-1}{3}$$
$$x - 7 = 0 \Rightarrow x = 7$$
**Final answer:**
$$x = \frac{-1}{3} \text{ or } x = 7$$
Quadratic Factoring C6D9Fc
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.