2x+3xy=x(2+3y)

5ab+10a^2=5a(b+2a)

a^4+a^3=a^3(a+1)

2n^5-4n^3=2n^3(n^2-2)

-3a^2y-12y^2=-3y(a^2-4y)

3c^6+7c^7-8c^8=c^6(3+7c-8c^2)