a²(m+n)³-a²b³
=a²[(m+n)³-b³]
=a²[(m+n)-b][(m+n)²+b(m+n)+b²]
=a²(m+n-b)(m²+2mn+n²+bm+bn+b²)
y²(x²-2x)³+y²
=y²[(x²-2x)³+1]
=y²(x²-2x+1)[(x²-2x)²-(x²-2x)+1]
=y²(x-1)²(x⁴-4x³+3x²+2x+1)
a²(m+n)³-a²b³
=a²[(m+n)³-b³]
=a²[(m+n)-b][(m+n)²+b(m+n)+b²]
=a²(m+n-b)(m²+2mn+n²+bm+bn+b²)
y²(x²-2x)³+y²
=y²[(x²-2x)³+1]
=y²(x²-2x+1)[(x²-2x)²-(x²-2x)+1]
=y²(x-1)²(x⁴-4x³+3x²+2x+1)