1. **State the problem:** Solve the quadratic equation $$x^2 + 10x + 13 = 4$$ by factoring. 2. **Rewrite the equation:** Move all terms to one side to set the equation to zero: $$x^2 + 10x + 13 - 4 = 0$$ which simplifies to $$x^2 + 10x + 9 = 0$$ 3. **Factor the quadratic:** We look for two numbers that multiply to 9 and add to 10. These numbers are 9 and 1. So, $$x^2 + 10x + 9 = (x + 9)(x + 1) = 0$$ 4. **Solve for x:** Set each factor equal to zero: $$x + 9 = 0 \implies x = -9$$ $$x + 1 = 0 \implies x = -1$$ 5. **Final answer:** The solutions are $$x = \{-9, -1\}$$. This matches the answer choice **light blue**.