We know that,

a³ + b³ = (a + b) (a² – a × b + b²)

Using this formula, we get

= (2x)³ + (3y)³

= (2x + 3y) [(2x)² – (2x) (3y) + (3y)²]

= (2x + 3y) (4x² – 6xy + 9y²)