1. **State the problem:** We are given the ages of three children: Ahmed is $n$ years old, Maria is twice as old as Ahmed, and Gia is 3 years older than Maria. The combined age of the three children is 38. We need to find the equation that models their combined age. 2. **Define variables:** - Ahmed's age = $n$ - Maria's age = $2n$ (twice Ahmed's age) - Gia's age = $2n + 3$ (3 years older than Maria) 3. **Write the equation for combined age:** $$n + 2n + (2n + 3) = 38$$ 4. **Simplify the equation:** $$n + 2n + 2n + 3 = 38$$ $$5n + 3 = 38$$ 5. **Interpretation:** The equation modeling the combined age is $$5n + 3 = 38$$. **Final answer:** The correct equation is $5n + 3 = 38$.