remember
ab+ac=a(b+c)
find common factors
factor each to find a
27f^2g^2=333ffgg
18f^2g^3=233ffggg
-3f^2g=-13ffg
common group is
3ffg=3f^2g
so rewrite as
3f^2g(9g)+3f^2g(6g^2)+3f^2g(-1)
undistribute
(3f^2g)(9g+6g^2-1)
rearange inner
(3f^2g)(6g^2+9g-1)
