Just remember that when you multiply or divide two numbers,

If the numbers have the same sign, the result is always positive.

If the numbers have opposite signs, the result is always negative.
As you can see, the numerical portion of the answer is always 6. The only question is whether the complete answer is 6 or –6. That's where the rule of same or opposite signs comes in.
Another way of thinking about this rule is that the two negatives cancel each other out to make a positive.
Similarly, look at these four division equations:In this case, the numerical portion of the answer is always 5. When the signs are the same, the result is positive, and when the signs are different, the result is negative.