15 разложите многочлен на множители x³-x²y-xy²+y³ c²+2c-d²+2d a³+a²b-ab²-b³ m²-2n-m-4n²

X³-x²y-xy²+y³=(x+y)(x²-xy+y²)-xy(x+y)=(x+y)(x²-xy+y²-xy)=(x+y)(x²-2xy+y²)=(x+y)(x-y)(x-y)
c²+2c-d²+2d=(c-d)(c+d)+2(c-d)=(c-d)(c+d+2)
a³+a²b-ab²-b³=(a-b)(a²+ab+b²)+ab(a-b)=(a-b)(a²+ab+b²+ab)=(a-b)(a+b)(a+b)
m²-2n-m-4n²=(m-2n)(m+2n)-2(m+2n)=(m+2n)(m-2n-2)