X³+y³= x+4y+x²-16y²= a³+27-3a-a²= x³+4x²+4x+16= 3x²-48xy+192y²= x²-6x+5=
X³+y³ = (x+y)(x²-xy+y²)x+4y+x²-16y² = (x+4y)(x-4y+1) a³+27-3a-a² = (a+3)(a²-4a+9) x³+4x²+4x+16 = (x+4)(x²+4) 3x²-48xy+192y² = 3(x-8y)² x²-6x+5 = (x-1)(x-5)