Vastaus: y = 1 x = 3 Selitys: # X + y = 4 # --- (1) # 2x-y = 5 # --- (2) Alkaen (1), # X + y = 4 # # X = 4-y # --- (3) 3 kohta (2) # 2x-y = 5 # # 2 (4-y) -y = 5 # # 8-2y-y = 5 # # 8-3y = 5 # # 3 = 3v # # Y = 1 # --- (4) 4 kohta (3) # X = 4-y # # X = 4-1 # # X = 3 #
