-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
If there was 31 dogwood trees already there and after there was a total of 96 dogwood trees therefore all you would have to do is subtract (96-31) you would get 65 so the answer is 65