1. The problem is to simplify the expression "u must to one number" which seems to imply converting or simplifying a variable or expression to a single number. 2. Since the problem is unclear, let's assume you want to simplify or evaluate an expression involving a variable u to a single number. 3. If you provide a specific expression or equation involving u, I can help simplify or solve it. 4. Please provide the exact expression or equation for u to proceed with simplification or evaluation.