| ( | 1 | ÷ | 40 | + | 1 | ÷ | 60 | ) | × | 27 | − | x | ÷ | 40 | = | 1 |
| Left side of the equation = | 1 | ÷ | 40 | × | 27 | + | 1 | ÷ | 60 | × | 27 | − | 1 40 | x |
| = | 27 40 | + | 9 20 | − | 1 40 | x |
| = | 9 8 | − | 1 40 | x |
9 8 | − | 1 40 | x | = | 1 |
| - | 1 40 | x | = | 1 | − | 9 8 |
| - | 1 40 | x | = | - | 1 8 |
1 8 | = | 1 40 | x |
1 40 | x | = | 1 8 |
| x | = | 1 8 | ÷ | 1 40 |
| = | 1 8 | × | 40 |
| = | 1 | × | 5 |
| x | = | 5 |