1)100a^2-a^4=а^2×(100-а^2)= a^2×(10-a)×(10+a)
2)18с^2-2-х-2х=18с^2-3, 3)x^4-y^6, 4) 9+y^2-x^2-6y=(3-y)^2-x^2=(3-y-x)×(3-y+x) 5)a^2-8a-81b^2+16=(a-4)^2-81b^2=(a-4-9b)×(a-4+9b), 6) a^2+3a×2=a^2+6a=a×(a+6), 7)x^2-8x+12=x^2-2x-6+12=x+(x-2)-6 (x-2)=(x-2)×(x-6), 8) a^2+12ax×11x^2=a^2+132ax^3=a×(a+132x^3)