√23 - x = x - 3
23 - x = ( x - 3)²
23 - x = x² - 6x + 9
- x² - x + 6x + 23 - 9 = 0
- x² + 5x + 14 = 0
x² - 5x - 14 = 0
D = b² - 4ac = 25 - 4 × ( - 14) = 25 + 56 = 81 = 9²
x1 = ( 5 +9) / 2 = 7
x2 = ( 5 - 9) / 2 = - 2
x1 × x2 = - 2 × 7 = - 14.
Ответ: произведение корней равно - 14.