Question: User: 40a-16a
1. **State the problem:** Simplify the expression $$40a - 16a$$.
2. **Formula and rules:** When subtracting like terms, subtract their coefficients and keep the variable the same.
3. **Intermediate work:**
$$40a - 16a = (40 - 16)a$$
4. **Simplify the coefficients:**
$$40 - 16 = 24$$
5. **Final expression:**
$$24a$$
6. **Explanation:** Since both terms have the same variable $$a$$, we subtract the numbers in front (coefficients) and keep the variable, resulting in $$24a$$.