12*-9 is simply 12 * 9 with a negative at the end. I use a strategy as I'm in 8th grade that I learned in 5th this should help. If you love to hat that is bad. this is for division and multiplication this is stating that if a positive( love ) number times or divided by a negative( hate ) number it is negative( bad ). so 12*9=108 and add the negative and your answer is -108
Hope this helps:) good luck!