72 : 8 + 57 = 66
54 : 9 * 12 = 72
70 * 8 + 40 = 600
780 : 6 : 5 = 26

Проверка:
$72 \overset{1}{:} 8 \overset{2}{+} 57 = 66$
1) 72 : 8 = 9
2) 9 + 57 = 66
 
$54 \overset{1}{:} 9 \overset{2}{*} 12 = 72$
1) 54 : 9 = 6
2) 6 * 12 = 72
 
$70 \overset{1}{*} 8 \overset{2}{+} 40 = 600$
1) 70 * 8 = 560
2) 560 + 40 = 600
 
$780 \overset{1}{:} 6 \overset{2}{:} 5 = 26$
1) 780 : 6 = (600 + 180) : 6 = 100 + 30 = 130
2) 130 : 5 = (100 + 30) : 5 = 20 + 6 = 26