We have,
⇒12m3+6m2−6m
⇒6m(2m2+m−1)
⇒6m(2m2+(2m−m)−1)
⇒6m(2m2+2m−m−1)
⇒6m(2m(m+1)−1(m+1))
⇒6m(m+1)(2m−1)
−2(1−m2)−4m2−(2−m2) equals
−2(1−m2)−4{m2−(2−m2)}=______.