1) (x - 1)(x - 2) + (x + 3)(x - 3) + 3x + 18 = 0
x² - 2x - x + 2 + x² - 9 + 3x + 18 = 0
2x² + 11 = 0
x² = - 5,5 - решений нет
2) (3x - 5)² - 5(5 - 6x) = 0
9x² - 30x + 25 - 25 + 30x = 0
9x² = 0
x² = 0
x = 0
3) (x - 7)² + 7(2x - 14) = 0
x² - 14x + 49 + 14x - 98 = 0
x² - 49 = 0
x² = 49