Answer:
For example, if N represents a number, then N + 9 is the number that is 9 greater than N.
So if N represents the number 3, then N + 9 is the number 12.
If N represents the number 7, then N + 9 is the number 16.
Here are 2 important terms for you to understand: Algebraic Expression and Algebraic Equation.
In the previous example, N + 9 is called an algebraic expression because N can represent any number.
If we write it this way: N + 9 = 12, we are writing an algebraic equation.
In an equation, N represents a specific number, not any number.
N + 9 = 12 means N is a number which, when added to 9, must give the answer 12.
So N can only be the number 3 because only 3 + 9 is equal to 12.
Step-by-step explanation: