Question

3 What should be added to 4x² + 4xy + y² to obtain (2x - y)²​

Answer 1

Answer:

- 8xy

Step-by-step explanation:

Let the number be a.

4x² + 4xy + y² + a = ( 2x - y )²

a = ( 2x - y )² - ( 4x² + 4xy + y² )

= 4x² - 4xy + y² - 4x² - 4xy - y²

= 4x² - 4x² - 4xy - 4xy + y² - y²

= 0 - 8xy + 0

a = - 8xy

Therefore, - 8xy should be added to 4x² + 4xy + y² to obtain ( 2x - y )²