Hej!
(x - 6)² - (x - 4)² = 4(x - 3)
x² - 12x + 36 - (x² - 8x + 16) = 4x - 12
x² + 12x + 36 - x² + 8x - 16 = 4x - 12
20x + 20 = 4x - 12
20x - 4x = -12 - 20
16x = -32 / : 16
x = -2
Pozdrawiam! - Julka