This question would be a lot better if you had actually included the exercises. When a question talks about other questions that you already did, you need to include those too. Otherwise we don't know what the question is talking about. Fortunately I was able to figure it out without seeing the exercises, but just for future reference, you should include that extra information.
When two addends(things you add together) are negative, adding them is a lot like adding positive numbers; you just have a negative sign on the sum. For example, 4 + 5 = 9 -4 + -5 = -9
Step-by-step explanation: the total of boxes the store has is 98 boxes of tiles. This is computed by dividing 56 by 7 which is equal to 392. Then 392 will be divided by 4 which will give us 98