a³ - b³ = (a - b)(a² + ab + b²)
a³ + b³ = (a + b)(a² - ab + b²)
a² - b² = (a - b)(a + b)
(x³ - 1)(x⁶ + x³ + 1) = x⁹ - 1
(x³ + 1)(x⁶ - x³ + 1) = x⁹ + 1
(x³-1)(x³+1)(x¹⁸+1)(x³⁶+1)(x⁶+x³+1)(x⁶ -x³+1) = (x⁹ - 1)(x⁹ + 1)(x¹⁸+1)(x³⁶+1) = (x¹⁸-1) (x¹⁸+1)(x³⁶+1) = (x³⁶-1)(x³⁶+1) = x⁷²- 1
