The answer to the question is in the image below. If you want to subtract mixed numbers with unlike denominators, you need to check the greatest common denominator between all of them.
-6 x 2 + 6 x 200. Since you want to find out 6 multiplied by 198 the easiest way (for me) would be to round it and then substract 12 since 200-198 is equal to 2 and 6 x 2 is equal to 12
