Answer:
The first one is -4 because pretend you had 5 green toy bears and 1 blue toy bears and you bring one of the bears and they fell down the mountain and then all you have is 4,4 means a negative so you have a -4,the second one is 0 and just do the same but don't use green toy bears because green toy bears stand for negative and blue toy bears stand for positive.I hope this helped.
Explanation: