By moving the signs he actually changed the number itself. He changed -6 from a negative to a positive and 5 from a positive to a negative. Both equations give different answers.
Hopefully this helps :)
Answer:
I don't know I need the answer choices
Step-by-step explanation:
Answer: The last line is a mistake
Step-by-step explanation: because you are not supposed to combine something that has a term and something that doesn't. So it should just stay has 40g+24