2/5+3/4-23/20 помогите пожалуйста
2/5 + 3/4 - 23/20 = 8/20 + 15/20 - 23/20 = 0 Пояснения: 2/5 = (2*4)/(5*4) = 8/20 - доп.множ. 4 3/4 = (3*5)/(4*5) = 15/20 - доп.множ.5 8/20 + 15/20 = 23/20 23/20 - 23/20 = 0