2) m³n³ + k³ = (mn + k)(m²n² - mnk + k²)
4) k^6 + (pq)^6 = (k² + p²q²)(k^4 - k²p²q² +p^4q^4)
6) (x - 2)³ - 27 = (x - 2 - 3)((x - 2)² + 3(x - 2) +3²) = (x -5)(x² - x + 7)
8) 27x³ - y³(x - y)³ = (3x - y(x - y))(9x² + 3xy(x - y) + y²(x - y)²) = (3x - xy + y²)(9x² + x²y² - 2xy³ + 3x²y - 3xy² +y^4)