1. **State the problem:** Solve for $a$ in the second question. 2. **Recall the second question:** Since the user refers to $a$ in the second question, identify the equation or expression involving $a$. 3. **Isolate $a$:** Use algebraic manipulation to solve for $a$. 4. **Show all steps clearly:** Simplify and solve step-by-step. 5. **Provide the final value of $a$.