1. **State the problem:** Simplify the expression $12x + 30$ by factoring. 2. **Formula and rules:** To factor an expression, find the greatest common factor (GCF) of all terms and factor it out. 3. **Find the GCF:** The GCF of $12x$ and $30$ is $6$. 4. **Factor out the GCF:** $$12x + 30 = 6 \times 2x + 6 \times 5$$ 5. **Write the factored form:** $$12x + 30 = 6(2x + 5)$$ 6. **Explanation:** Factoring helps simplify expressions and solve equations more easily by grouping common factors. **Final answer:** $6(2x + 5)$