-(a-b) × (a²+ab+b²)
-(x-1/y) × (x²+x/y+1/y²)
(a²+1) × (a^4-a^2+1)
(xy-1) × (x²y²+xy+1)
(mn+2) × (m²n²-2mn+4)
-1/8(1+2a) × (1-2a+4a²)
-(a-b) × (a²+ab+b²)
-(x-1/y) × (x²+x/y+1/y²)
(a²+1) × (a^4-a^2+1)
(xy-1) × (x²y²+xy+1)
(mn+2) × (m²n²-2mn+4)
-1/8(1+2a) × (1-2a+4a²)