Verified Answer :

  • Identify the expression as a subtraction of a negative integer: \(-1 - (-3)\).
  • Use the rule that subtracting a negative is equivalent to adding the corresponding positive integer: \(-1 - (-3) = -1 + 3\).
  • Simplify the addition \(-1 + 3\) to find the result: \(2\).
  • The final answer is \(\boxed{2}\).

Explanation

  1. Understanding the Subtraction of Negative Numbers

The problem asks us to evaluate the expression \(-1 - (-3)\). We are subtracting a negative integer from another integer. The key property to apply here is the rule for subtracting negative numbers: subtracting a negative value is equivalent to adding its positive counterpart (the additive inverse). Mathematically, this is expressed as \(a - (-b) = a + b\).

  1. Performing the Calculation

Using the rule \(a - (-b) = a + b\), we can substitute \(a = -1\) and \(b = 3\). The expression \(-1 - (-3)\) then becomes \(-1 + 3\). Adding \(-1\) and \(3\) is equivalent to \(3 - 1\), which results in \(2\).

  1. Conclusion

The calculation \(-1 - (-3) = -1 + 3 = 2\) shows that the result of the expression is \(2\). Thus, \(\boxed{2}\).

Examples

Think of temperature in a cold region. If the current temperature is \(-1^\circ\text{C}\) and it increases by \(3^\circ\text{C}\), you subtract a negative change in heat. More intuitively, if your bank balance is \(\$ -1\) (meaning you owe the bank \(\$1\)) and you "subtract" a debt of \(\$3\) (meaning the debt is forgiven or removed), your balance effectively increases. Specifically, \(-1 - (-3) = -1 + 3 = 2\), leaving you with a positive balance of \(\$2\). This demonstrates how subtracting negative values is essential for tracking changes in balance, altitude, or temperature.