if you add 2 negative numbers the result will also be negative but with a greater absolute value (the distance from a number to 0) Because if you have a debt and then you owe more you'll be farther away from having 0 dollars.
If you add a negative number and a positive number the result, will have the sign of the number with the greatest absolute value.
If you have 3 dollars and owe 5 dollars you'll still owe 2 dollars, because you owe more money for what you have. If by the other hand you have 10 dollars and a debt of 5 dollars you'll pay the debt and still conserve 5 dollars because you have more money than debt.
If you subtract two negative numbers the results may vary. If the first number has the least absolute value the result will be positive. if you owe 3 dollars and subtract 5 dollars of debt you'll have two dollars because you subtract more debt than what you have. If the first number has the greatest absolute value then the result will be negative. If you have a debt of 8 dollars and you subtract a debt of 3 you'll be nearer to 0 but still, have a debt.
.If you subtract a positive number from a negative number the result will be negative. if you subtract money and you already have a debt you'll have more debt. If you subtract a negative number from a positive number the result will be positive. If you have 3 (including a debt) dollar and you subtract part of that debt you'll have more money.
If you subtract two positive numbers the result will be negative if you subtract more of what you have, and positive if you subtract less than what you have. 3-4=-1, 3-2=1