(3х2х^3 - 4х) -12х^2.

3х ✖ (2х³ ➖ 4х) ➖ 12х² = 3х✖️ (2х³ ➖ 4х ➖4х) = 3х * (2х³ -8х) = 3х*2х*(х²-4) = 3х*2х*(х-2) * (х+2) = 3х² * 2 (х-2) * (х+2) = 3 * 2х² * (х-2) * (х+2) = 6х² * (х-2) * (х+2)