Answer:
The answer to your question is: the third option is correct.
Step-by-step explanation:
This is an addition of cubes which formula is:
(x³ + y³ ) = (x + y)(x² - xy + y²)
In your exercise, x = x and y = 4y
Then
(x³ + 64y³) = (x + 4y)(x² - 4xy + 16y²)
