a³ - b³ = (a - b)(a² + ab + b²)
a² - b² = (a - b)(a + b)
(2 - 3x)(4+6x+9x²)+3x(3x-1)(3x+1)=0
(2-3x)(2²+2*3x+(3x)²)+3x((3x)²-1²)=0
8 - 27x³ + 3x(9x² - 1) = 0
8 - 27x³ + 27x - 3x = 0
x = 8/3
