Minus Sign 9C9F31

1. The user's question is unclear and incomplete, but it seems to ask about why a question must have a minus sign or why a question must be negative. 2. Since the question is ambiguous, let's clarify that in mathematics, a minus sign is used to indicate subtraction or a negative value. 3. If the question is about why a minus sign is necessary in certain problems, it is because it changes the value or direction of a number. 4. For example, in subtraction, $a - b$ means you take away $b$ from $a$. 5. In negative numbers, $-x$ means the opposite of $x$ on the number line. 6. Without a minus sign, the meaning of the expression would be different. 7. Therefore, the minus sign is essential to convey the correct mathematical operation or value. Final answer: The minus sign is necessary to indicate subtraction or negative values, which changes the meaning of a mathematical expression.