Odpowiedź:
X2+2x-2x-4=5
X2=5+4
X2=9
X=3 lub x=-3
Czołem!
(x - 2)(x + 2) = 5
x² - 2² = 5
x² - 4 = 5
x² - 4 - 5 = 0
x² - 9 = 0
(x + 3)(x - 3) = 0
x + 3 = 0 ➡️ x = -3
x - 3 = 0 ➡️ x = 3
