1. **State the problem:** Solve the equation $$4^x = ?$$ (assuming the equation is to solve for $x$ in $4^x = y$ or similar, but since the right side is missing, we interpret the problem as solving $4^x = 4^x$ or clarifying the expression. 2. **Formula and rules:** The exponential function $4^x$ means 4 raised to the power of $x$. 3. **If the problem is to solve $4^x = 4^x$, then any $x$ satisfies the equation.** 4. **If the problem is incomplete, please provide the full equation to solve for $x$.**