Respuesta :

Answer:

Helena gave the answer as (7y²z + 6yz²- 5 - 3yz² + 2) which is equivalent to (7y²z + 3yz² - 3).

Step-by-step explanation:

Misha's group was asked to write an expression equivalent to  

7y²z + 3yz² - 3

When Mr. Chen checked their answers, he found only one to be correct.

And she was Helena.

Helena gave the answer as (7y²z + 6yz²- 5 - 3yz² + 2) which is equivalent to (7y²z + 3yz² - 3).  

Because, (7y²z + 6yz²- 5 - 3yz² + 2)

= 7y²z + (6yz² - 3yz²) - (5 - 2)  

= 7y²z + 3yz² - 3 (Answer)