The expression -7 - 2 involves a basic mathematical operation, subtraction. Subtraction is the process of finding the difference between two numbers. In this case, we have two numbers: -7 and 2.
First, consider -7. It is a negative integer, indicating a value that is less than zero. It's positioned to the left on the number line, representing a deficit or a decrease from zero.
Now, let's introduce the positive integer 2. It represents a quantity greater than zero and is located to the right on the number line, signifying an addition or an increment.
To calculate -7 - 2, we need to subtract 2 from -7. This involves moving 2 units to the left on the number line starting from -7. As a result, we arrive at -9.
The expression -7 - 2 is solved by subtracting 2 from -7, leading to the answer -9.