Примеры 30 - x = 18 9\50 17\40 + x = 1 x - 4 8\49 = 41\49

30-х=18 9/50
х=30-18 9/50
х=29 50/50-18 9/50
х=11 41/50

17/40+х=1
х=1-17/40
х=40/40-17/40
х=23/40

х-4 8/49=41/49
х=41/49+4 8/49
х=5

2) х=1-17/40=40/40-17/40=(40-17)/40=23/40