Answer:
1. 3x-7y and -7y+3x
Explanation:
1. 3x -7y and -7y +3x
This is correct because the terms remain unchanged. The -7y stays a -7y and the positive 3x stays a positive 3x.
2. 3x -7y and 7y -3x
This is not correct because the signs of the 3x and 7y switch. For the expressions to be equivalent, the signs must remain unchanged.
3. 3x -7y and 3y -7x
This is not correct because the variables of the 3 and 7 switched. The variables need to stay the same, for the expressions to be equivalent.
4. 3x-7 and -3y+7x
This is not correct because both the variables and the signs of the expressions changed. Both the signs and variables would need to stay the same in order to be equivalent.