Question

Which pair of numbers is a sum of zero? -2,-1,0,1

Answer 1

Let's say you have a dollar and you use a vending machine to buy candy which costs a dollar. How much money do you have left?

Answer 2

I just need the answer

Answer 3

I'll give an example that leads to the answer. Apply this example to your question
My meal costs 2 dollars, I paid 2 dollars, and I have no change left so
-2+2 = 0