Answers:
1) Equivalent
2) Equivalent
3) Not equivalent
Step-by-step explanation:
When there is a plus sign or nothing in front of a number, it means it’s positive.
Example:
3x+6
Both 3x and 6 are positive.
When there is a negative or minus sign in front of a number, it means it’s negative.
Example:
6-2
2 is negative and 6 is positive.
We can rearrange numbers in equations just as long as we also carry whether or not they are positive or negative.
Example:
3x+9-16 can be rewritten as:
-16+9+3x
Notice how the minus sign in front of the 16 is carried with the 16.
In the expressions in your picture, the first two are equal because the numbers have been rearranged properly. However, for the last problem:
6z-2z+4
Notice how 6z and 4 are positive and -2z is negative.
When they rearranged the expression, 6z became positive and 2z became negative, which shouldn’t have happened.
I hope this helps! Please comment if you have any questions.