1. David B. is correct, while Issac N. is wrong. David B. correctly only distributed the 3 to the numbers in the parentheses, while Issac N. distributed the 3 to the x outside of the parentheses. The x wasn’t inside the parentheses, which means the x shouldn’t have been multiplied by the 3.
2. Calculator Boy is correct, while Mathy Girl is wrong. After Calculator Boy distributed the 2, he correctly calculated that the 8x could not be subtracted by the “-6 -7”. It left his equation with “8x -13” as the -6 and -7 would combine. Mathy Girl distributed correctly as well, however, she wrote that you could subtract the “-6” from the “8x” which cannot happen. The -6 does not have a variable (x), so it cannot subtract from the “8x”.
I apologize if the explanation is a bit confusing… comment if you would like extra help and I can try to explain it differently!