pre # X ^ 2-6x + 8 = 0 # # 0 = x ^ 2-4x-2x + 8 # # 0 = x (x-4) -2 (X-4) # # 0 = (x-4), (x-2) # # (X-4) = 0 # OR # (X-2) = 0 # # X = 4 # OR # X = 2 # pre # x = 4 a 2 # # X ^ 2-6x + 8 # je nula z toho dôvodu # 4 a 2 # faktory
