x − 352 = 648
x = 648 + 352
x = 1000
Проверка:
1000 − 352 = 648
648 = 648
 
Вычисления:
$\snippet{name: op_column, sign: '+', x: '648', y: '352', z: '1000'}$
 
$\snippet{name: op_column, sign: '-', x: '1000', y: '352', z: '648'}$
 
704 − x = 198
x = 704 − 198
x = 506
Проверка:
704 − 506 = 198
198 = 198
 
Вычисления:
$\snippet{name: op_column, sign: '-', x: '704', y: '198', z: '506'}$
 
$\snippet{name: op_column, sign: '-', x: '704', y: '506', z: '198'}$
 
x * 9 = 720
x = 720 : 9 = 72 д : 9 = 8 д
x = 80
Проверка:
80 * 9 = 720
8 * 9 * 10 = 720
72 * 10 = 720
720 = 720
 
300 : x = 60
x = 300 : 60 = 30 : 6
x = 5
Проверка:
300 : 5 = 60
30 д : 5 = 60
6 д = 60
60 = 60
 
x : 78 = 9
x = 78 * 9 = (70 + 8) * 9 = 70 * 9 + 8 * 9 = 630 + 72
x = 702
Поверка:
702 : 78 = 9
9 = 9
 
17 * x = 85
x = 85 : 17
x = 5
Проверка:
17 * 5 = 85
(10 + 7) * 5 = 85
10 * 5 + 7 * 5 = 85
50 + 35 = 85
85 = 85