| ( | 1 | ÷ | 7 | ) | x | + | ( | 338 | − | x | ) | ( | 1 | ÷ | 3 | ) | = | 78 |
| Left side of the equation = | 1 | ÷ | 7 | × | x | + | ( | 338 | − | x | ) | ( | 1 | ÷ | 3 | ) |
| = | 1 7 | x | + | ( | 338 | − | x | ) | ( | 1 | ÷ | 3 | ) |
| = | 1 7 | x | + | 338 | ( | 1 | ÷ | 3 | ) | − | x | ( | 1 | ÷ | 3 | ) |
| = | 1 7 | x | + | 338 | × | 1 | ÷ | 3 | − | x | ( | 1 | ÷ | 3 | ) |
| = | 1 7 | x | + | 338 3 | − | x | ( | 1 | ÷ | 3 | ) |
| = | 1 7 | x | + | 338 3 | − | x | × | 1 | ÷ | 3 |
| = | 1 7 | x | + | 338 3 | − | x | × | 1 3 |
| = | - | 4 21 | x | + | 338 3 |
| - | 4 21 | x | + | 338 3 | = | 78 |
| - | 4 21 | x | = | 78 | − | 338 3 |
| - | 4 21 | x | = | - | 104 3 |
104 3 | = | 4 21 | x |
4 21 | x | = | 104 3 |
| x | = | 104 3 | ÷ | 4 21 |
| = | 104 3 | × | 21 4 |
| = | 26 | × | 7 |
| x | = | 182 |