1) (а+2)(х+6)= ах+6а+2х+12
( 2х² + 4)(8х² - 3)= 16x^4 - 6x² + 32x² - 12 = 16x^4 + 26x² - 12
(a-3)(3a²-5a+2)= 3a³ - 5a² + 2a - 9a² -15a -6 = 3a³ -14a² +13a - 6
2)(3z-2)(5z +3)-(2z-1)(7z+2) = -4
15z + 9z -10z - 6 - 14z+4z - 7z -2 = -4
14z - 6 - 11z - 2 = - 4
3z = -4 +6 +2
3z= 4
z= 4:3
z=1,3