Question 253152
-23-73=-96
Think of it as adding two regular numbers but they both have  a minus sign.
I am sure you can do 73-23=50 and -23+73=50

also you can think of it as I owe John  73 cents and I owe Mary 23 cents
James owes me 15 cents
-73-23+15=-93+15=-78

What you owe is negative (going out)and what they owe you is positive. (coming in)