Hej!
2x - x(x - 5) + (x² - 1) = 5(x + 3) - x(x - 2)
2x - x² + 5x + x² - 1 = 5x + 15 - x² + 2x
7x - 1 = -x² + 7x + 15
7x - 1 + x² - 7x - 15 = 0
x² - 16 = 0
(x + 4)(x - 4) = 0
x + 4 = 0 lub x - 4 = 0
x = -4 lub x = 4
Pozdrawiam! - Julka
