Question

Which of the following is the correct factorization of the polynomial below? x^3-15

Answer 1

Answer with explanation:

Use the identity to solve the problem

$a^3 -b^3=(a-b)(a^2+ab+b^2)\\\\x^3-15=x^3-(15^{\frac{1}{3})^3}\\\\=[x-(15)^{\frac{1}{3}}][x^2+(15)^{\frac{1}{3}}x+((15)^{\frac{1}{3}})^{2}]\\\\=[x-(15)^{\frac{1}{3}}][x^2+(15)^{\frac{1}{3}}x+(15)^{\frac{2}{3}}]$  

Answer 2

The polynomial is irreducible.