!) =7(x^2-4)=7(x-2)(x+2)
2) =3a(a^2-36)=3a(a-6)(a+6)
3) =3x^2(x^2-y^2)=3x^2(x-y)(x+y)
4)=4m^2(n^4-16p^4)=4m^2(n^2-4p^2)(n^2+4p^2)= =4m^2(n--2p)(n+2p)(n^2+4p^2)
5) =3(x^2-16xy+64y^2)=3(x-8y)^2
6) = -3b^2(25b^4-10b^2+1)= -3b^2(5b^2-1)^2
7) =2(x^6-y^9)=2(x^2-y^3)(x^4+x^2y^3+y^6)
8) =a^3(a-b)+b^3(a-b)=(a^3+b^3)(a-b)=(a+b)(a^2-ab+b^2)(a-b)
9) = x+4y+(x-4y)(x+4y)=(x-4y)(x+4y)^2
10) =y^5(x^2-1)-y^2(x^2-1)=(y^5-y^2)(x^2-1)=y^2(y^3-1)(x-1)(x+1)=
=y^2(y-1)(y^2+y+1)(x-1)(x+1)