Final answer:
In the expression 9x, the number 9 is the coefficient being multiplied by x, indicating the operation is multiplication.
Step-by-step explanation:
In the expression 9x, the number 9 is the coefficient that is being multiplied by the variable x. In algebra, this operation indicates multiplication rather than division, addition, or subtraction. When we multiply two numbers, the sign of the result depends on the signs of the numbers being multiplied. If both numbers are positive or both are negative, the result is positive. If one number is positive and the other is negative, the result is negative. Division follows the same rules regarding the signs. It's important to understand that when we multiply or divide both sides of an equation by the same number, we do not change the equality of the equation.