Question

Factor the following polynomial using the formula for the difference of two cubes. y^(3)-729

Answer 1

(y - 9)(y² + 9y + 81)

Explanation:

a difference of cubes is factored in general as

a³ - b³ = (a - b)(a² + ab + b² )

given

y³ - 729

= y³ - 9³ ( with a = y and b = 9 )

= (y - 9)(y² + 9y + 9²)

= (y - 9)(y² + 9y + 81) ← in factored form