Step-by-step explanation:
The expression "X + 9" represents a mathematical operation involving addition. In this case, we are adding the variable X to the number 9.
To evaluate this expression, you would substitute a specific value for the variable X and then perform the addition. For example, if X equals 3, then the expression would become 3 + 9, which equals 12. Similarly, if X is equal to -5, then the expression would be -5 + 9, resulting in 4.
The value of X can be any real number, positive or negative. When you add a number to another number, the result is called the sum. So, in this case, the sum of X and 9 is X + 9.
