It looks like you are asking for an evaluation involving \( x = 3 \), but I need more context to provide a specific answer.
Could you please provide the expression or equation in which you want to substitute \( x = 3 \)? For example, if you have an expression like \( 2x + 5 \), it would become \( 2(3) + 5 \) when you substitute \( 3 \) for \( x \).
Let me know the exact expression you want evaluated!