What is #7\times ( - 7) #?
The answer is -49.
When you multiply integers, there are a few rules. First, when you multiply a positive number by a negative number, the answer will always be negative. But, when you multiply a positive by a positive or a negative by a negative, the answer will always be positive.
One way to think about this is to consider positive numbers as money I actually have and negative numbers as amounts I owe to other people.
Then if I owed
then I would have