2(4x−12)2−7(4x−12)+6=0
2(4x - 12)² - 7(4x - 12) + 6 = 0
Сделаем замену :
4x - 12 = m
2m² - 7m + 6 = 0
D = (- 7)² - 4 * 2 * 6 = 49 - 48 = 1