Explain, using a real-world example of debt, why subtracting a negative number is the same as adding a positive number
(e.g., 10 − (−5) = 15).

Imagine you have 10 rupees in cash but also owe a friend 5 rupees, making your total financial position (10 − 5). If your friend generously cancels or subtracts that 5 rupee debt (−5), you no longer owe that money. Removing this negative financial burden increases your net worth back to 15 rupees.
Removing a debt of 5 can be written as
10 − (−5), which gives the exact same result as adding 5 rupees.