Question

Someone knows it, I need help

Answer 1

The answer is A.

Explanation:

In order to simplify, you have to collect like terms :

x² - 3xy - 5xy - 7y² + 4x² + 8y²

= (x² + 4x²) + (-3xy - 5xy) + (-7y² + 8y²)

= 5x² - 8xy + y²