1) 2(3х-4)² - (2х-3)(4х²+6х+9) - 2х(3-2х)(3+2х)=
=2(9х²-24х+16) -((2х)³-3³)-2х(9-4х²)=
=18х²-48х+32-8х³+27-18х+8х³=18х²-66х+59;
2) (7х-3)² - (3х+5)(3х-2) - 10(7-2х)²=
=(49х²-42х+9)-(9х²+15х-6х-10)-10(49-28х+4х²)=
=49х²-42х+9-9х²-15х+6х+10-490+280х-40х²=
=229х-471;
3) (2х-7)²-(4х+3)²+(3-4х)²-(2х+6)²=
можно разложить на множители по формуле разности квадратов
=(2х-7-4х-3)(2х-7+4х+3) +(3-4х-2х-6)(3-4х-2х-6)=
=(-2х-10)(6х-4)+(-6х-3)(-6х-6)=
=-12х²-60х+8х+40+36х²+18х+36х+18=
=24х²+2х+58;
4)(3х+1)(9х²-3х+1)-3х(5-3х)²+5(3х-2)²+19=
=(3х)³-1³-3х(25-30х+9х²)+5(9х²-12х+4)+19=
=27х³-1-75х+90х²-27х³+45х²-60х+20+19=
=135х²-135+38.