Someone came into my shop and stole $100.00 from the register without my knowledge. the person came back in with the same $100.00 five minutes later and he bought $70.00 worth of items and gave him back $30.00 in change. how much money did i lose?

Let's do this step by step, we know that the guy steals $ 100 So it would be - $ 100 for the store. The men buy $ 70 merchandise WITH THE MONEY THAT HE STOLE, but the money that he stole CAME BACK to the store So up to this poin, : - $ 100 + $100 - $ 70 = - $ 70 for the store After that , the store give $ 30 cash back, So in the and : - $ 70 - $30 = - $ 100 lost for the store