Answer:
say you buy something for 10 dollars, you are going to get charged for it, but if you take item off of your shopping cart you are taking away the -10 dollars that wouldve been charged.
Step-by-step explanation:
the reason this works is because you take away something that makes it less.
- (-7) is basically just saying delete that -7. that's why - (-7) is the same as +7
