| X | − | 1 | ÷ | 5 | × | X | = | 40 | − | X | + | 1 | ÷ | 5 | × | X |
| Left side of the equation = | X | − | 1 5 | X |
| = | 4 5 | X |
4 5 | X | = | 40 | − | X | + | 1 | ÷ | 5 | × | X |
| Right side of the equation = | 40 | − | X | + | 1 5 | X |
| = | 40 | − | 4 5 | X |
4 5 | X | = | 40 | − | 4 5 | X |
4 5 | X | + | 4 5 | X | = | 40 |
8 5 | X | = | 40 |
| X | = | 40 | ÷ | 8 5 |
| = | 40 | × | 5 8 |
| = | 5 | × | 5 |
| X | = | 25 |