1)
195c²p^5-91c^5p^6+221c³p^10=c²p^5(195-91c³p+221cp^5)
2)
(c+2)-d(c+2)=(c+2)(1-d)
3)
11p(c+8d)-9(8d+c)=(8d+c)(11p-9)
4)
7x(a-b)-5(b-a)=7x(a-b)+5(a-b)=(a-b)(7x+5)
5)
4c(4c-1)-3(4c-1)²=(4c-1)(4c-3(4c-1)(4c-12c+3)=(4c-1)(3-8c)
6)
8(a-4)²+(a-4)=[(a-4)[(8(a-4)+1]=(a-4)(8a³-31)