(4х²-1)(9х³+5)-(6х³-1)²=(2х-1)(2х+1)(9х³+5)-(6х³-1)(6х³+1)=(2х-1)(2х+1)(9х³+5)-(2х-1)(4х²+2х+1)(2х+1)(4х²-2х+1)=(2х-1)(2х+1)(9х³+5-4х²-2х-1+4х²-2х+1)=(2х-1)(2х+1)(9х³+5-4х)
но це ще не точно)
(4х²-1)(9х³+5)-(6х³-1)²=(2х-1)(2х+1)(9х³+5)-(6х³-1)(6х³+1)=(2х-1)(2х+1)(9х³+5)-(2х-1)(4х²+2х+1)(2х+1)(4х²-2х+1)=(2х-1)(2х+1)(9х³+5-4х²-2х-1+4х²-2х+1)=(2х-1)(2х+1)(9х³+5-4х)
но це ще не точно)