Answer:
(4x + 5y)(16x² - 20xy + 25y² )
Explanation:
given
64x³ + 125y³
this is a sum of cubes and factorises in general as
a³ + b³ = (a + b)(a² - ab + b²)
64x³ + 125y³
= (4x)³ + (5y)³ → with a = 4x and b = 5y
= (4x + 5y)((4x)² - 4x(5y) + (5y)² )
= (4x + 5y)(16x² - 20xy + 25y²) ← in factored form