Válasz: # x = 4, -7 # Magyarázat: # x ^ 2 +3 x -28 = 0 # # x ^ 2 +7 x - 4 x -28 = 0 # #x (x + 7) -4 (x + 7) = 0 # # (x + 7) (x-4) = 0 # Bármelyik # (x + 7) = 0, vagy (x-4) = 0 # Ha # x + 7 = 0 # #x = -7 # Ha # x-7 = 0 # # x = 4 # #x = 4, -7 #