- Identify that subtracting a negative number is equivalent to addition: \(-2 - (-4) = -2 + 4\).
- Recognize that adding a negative number is equivalent to subtraction: \(-2 + 4 + (-18) = -2 + 4 - 18\).
- Calculate the result step-by-step: \(-2 + 4 = 2\), and \(2 - 18 = -16\).
- The final result is \(\boxed{-16}\).
Explanation
- Analyzing the Expression and Rules
We are given the expression \(-2 - (-4) + (-18)\). To simplify this, we need to apply the fundamental rules of arithmetic regarding the signs of integers:
- Subtracting a negative number is equivalent to adding its positive counterpart: \(a - (-b) = a + b\).
- Adding a negative number is equivalent to subtracting its positive counterpart: \(a + (-b) = a - b\).
These rules allow us to rewrite the expression with standard addition and subtraction operations, making it much easier to evaluate.
- Performing the Calculations
Now we apply the rules identified in the first step to rewrite the expression:
- For the term \(-(-4)\), the subtraction of a negative value becomes addition: \(-(-4) = +4\).
- For the term \(+(-18)\), adding a negative value becomes subtraction: \(+(-18) = -18\).
Substituting these into our original expression, we get:
\(-2 + 4 - 18\)
Now, we perform the operations sequentially from left to right:
- First, \(-2 + 4 = 2\).
- Next, we take this result and subtract 18: \(2 - 18 = -16\).
- Final Result
After applying the arithmetic rules and performing the sequence of additions and subtractions, we have determined that \(-2 - (-4) + (-18) = -16\). The final simplified value is \(\boxed{-16}\).
Examples
Think of this calculation in terms of a bank account balance. If you start with a debt of \(\$2\) (\(-2\)), and then you receive a refund of \(\$4\) (\(-(-4)\)), your balance increases. However, if you then have a recurring monthly fee of \(\$18\) (\(+(-18)\)), your total balance decreases. By following the order of operations, you can track your net balance, which in this case leads to a total debt of \(\$16\), or \(\boxed{-16}\). This illustrates how tracking positive and negative values is essential for managing personal finances effectively.