Vastaus: # Y = 1/7 # # X = 27/7 # Selitys: a)# X + y = 4 # b)# 2x-5y = 7 # Kerro ensin a) -2: lla a)# -2x-2y = -8 # b)# 2x-5y = 7 # Lisää sitten a) ja b) # -7y = -1 => y = 1/7 # Korvaa y a) # X + 1/7 = 4 # # X = 4-1 / 7 = 27/7 #
