1) m+kn-n-km= m(1-k)-n(1-k)= (1-k)(m-n)
2) y³-by²-3b²y+3b³= y²(y-b)-3b²(y-b)= (y-b)(y²-3b²)
3) c(a-b)+(a-b)= (a-b)(c+1)
4) 8ab²-7b²c-14c³+16ac²= 8a(b²-c²)-7c(b²-c²)= (8a-7c)(b-c)(b+c)
5) an²-am³+cm³-cn²+bn²-bm³= a(n²-m²)-c(n²-m³)+b(n²-m³)= (n²-m³)(a-c+b)
6) 4a²(4a-3)-4a(4a-3)+4a-3= (4a-3)(4a²-4a+1)= (4a-3)(2a-1)²= (4a-3)(2a-1)(2a-1)