Answer:
The error with mark’s work is that a negative times a negative will give a positive. So -3 times -5 is +15 not -15. Then 15 times -2 will get you -30.
Answer:
His answer is wrong because -3 time -5 is 15 and then if he multiply 15 times -2 he would have get -30 not positive 30. This where he made mistanke
