1) a³-(b+1)³=(a-(b+1))(a²+a(b+1)+(b+1)²)=(a-b+1)(a²+ab+a+b²+2b+1)
2)(a-1)³+(b+1)³=a³-3a²+3a-1+b³+3b²+3b+1=a³+b³-3a²+3b²+3a+3b=(a+b)(a²-ab+b²)-3(a²-b²)+3(a+b)=(a+b)(a²-ab+b²)-3(a-b)(a+b)+3(a+b)=(a+b)(a²-ab+b²-3(a-b)+3)=(a+b)(a²+b²-ab-3a+3b+3)
3) 5a³+5b³-3a²+3b²=5(a³+b³)-3(a²-b²)=5(a+b)(a²-ab+b²)-3(a-b)(a+b)=(a+b)(5(a²-ab+b²)-3(a-b))=(a+b)(5a²+5ab+5b²-3a+3b)
4) 16x³+54y³=2(8x³+27y³)=2(2x+3y)(4x²-6xy+9y²)
5) 8a³-b³+4a²+2ab+b²=(2a-b)(4a²+2ab+b²)+4a²+2ab+b²=(2a-b+1)(4a²+2ab+b²)