( х + 6 ) ( 2х + 6 ) - 20 = 0
2х2 + 6х + 12х + 36 - 20 = 0
2х2 + 18х + 18 = 0
х1 + х2 = -9
х1х2 = 9
х1 = -7.85
х2 = -1.15
х2 =
( х + 6 ) ( 2х + 6 ) - 20 = 0
2х2 + 6х + 12х + 36 - 20 = 0
2х2 + 18х + 18 = 0
х1 + х2 = -9
х1х2 = 9
х1 = -7.85
х2 = -1.15
х2 =