Answer:
x³ + 9x²y + 27xy² + 27y³
Step-by-step explanation:
( x + 3y )² =
(x + 3y)(x + 3y) =
x² + 3xy + 3yx + 9y² =
x² + 6xy + 9y²
(x + 3y)(x² + 6xy + 9y²) =
x³ + 6x²y + 9xy² + 3yx² + 18xy² + 27y³ =
Hope this helps :)
