280 − 80 : 4 * 5 = 180
(720 − 90) : (25 + 65) = 7
57 : (3 + 16) = 3
(96 − 26) : 14 = 5

Вычисления:
$280 \overset{3}{-} 80 \overset{1}{:} 4 \overset{2}{*} 5 = 180$
1) 80 : 4 = 20
2) 20 * 5 = 100
3) 280 − 100 = 180
 
$(720 \overset{1}{-} 90) \overset{3}{-} (25 \overset{2}{+} 65) = 7$
1) 720 − 90 = 630
2) 25 + 65 = 90
3) 630 : 90 = 63 : 9 = 7
 
$57 \overset{2}{:} (3 \overset{1}{+} 16) = 3$
1) 3 + 16 = 19
2) 57 : 19 = 3
 
$(96 \overset{1}{-} 26) \overset{2}{:} 14 = 5$
1) 96 − 26 = 70
2) 70 : 14 = 5