Answer:
see explanation
Step-by-step explanation:
Given
5x³ + 40 ← factor out 5 from each term
= 5(x³ + 8)
x³ + 8 ← is a sum of cubes and factors in general as
a³ + b³ = (a + b)(a² - ab + b²)
x³ + 8
= x³ + (2y²)³ → a = x and b = 2y²
= (x + 2y²)(x² - 2xy² + 4)
Hence
5x³ + 40
= 5(x + 2y²)(x² - 2xy² + 4) ← in factored form