а) (a-b)²-a(a+2b) = a²-2ab+b²-a²-2ab = b²-4ab
б) 4c(c-2)-(c-4)² = 4c²-8c-(c²-2*c*4+4²) = 4c²-8c-(c²-8c+16) = 4c²-8c-c²+8c-16 =3c²-16
а) (a-b)²-a(a+2b) = a²-2ab+b²-a²-2ab = b²-4ab
б) 4c(c-2)-(c-4)² = 4c²-8c-(c²-2*c*4+4²) = 4c²-8c-(c²-8c+16) = 4c²-8c-c²+8c-16 =3c²-16