18 The two negatives will cancel out when multiplying, so the result will be a Positive number.
So, just pretend the signs dont exist...
2 x 9 = 18
NOTE... When you multiply a bunch of numbers, look at how many of these numbers are negative. If the answer to that question is an Even number, then the product will be Positive. If the answer to that question is an Odd number, then the product will be Negative.
Example: -3 x 4 x 6 x -5 x -7 x 3 = ....
Since three of those numbers are negative (and THREE is odd), then the product will be Negative.