(30/7 * 14/45 - 8 + 50/11)*3 = (4/3 - 8 + 50/11)*3 = 4/3 * 3 - 24 + 150/11 = 4-24+50/11 = 50/11 - 20 = 50/11 - 220/11 = - 170/11 = -15 5/11
98/10 : (9 15/15 - 3 7/15)*28/27 = 98/10 : (6 8/15)*28/27 = 98/10:98/15*28/27 = 98/10 * 15/98 * 28/27 = 14/9 = 1 5/9