Решить пример - ( 1 17/25 * 2 1/7 - 2 4/7 * 1 2/5 ) * 2 7/9
117/25*21/7=117/25*3=351/25 24/7*12/5=288/35 351/25-288/35=2457/175-1440/175=1017/175 1017/175*27/9=скорочуем113/175*27=3051/175