| ( | X | − | 39 | ) | × | 4 | ÷ | 5 | = | 3 | ÷ | 7 | × | X | + | 39 |
| Left side of the equation = | ( | X | − | 39 | ) | × | 4 5 |
| ( | X | − | 39 | ) | × | 4 5 | = | 3 | ÷ | 7 | × | X | + | 39 |
| Left side of the equation = | X | × | 4 5 | − | 39 | × | 4 5 |
| = | X | × | 4 5 | − | 156 5 |
4 5 | X | − | 156 5 | = | 3 | ÷ | 7 | × | X | + | 39 |
| Right side of the equation = | 3 7 | X | + | 39 |
4 5 | X | − | 156 5 | = | 3 7 | X | + | 39 |
4 5 | X | − | 3 7 | X | = | 39 | + | 156 5 |
13 35 | X | = | 39 | + | 156 5 |
13 35 | X | = | 351 5 |
| X | = | 351 5 | ÷ | 13 35 |
| = | 351 5 | × | 35 13 |
| = | 27 | × | 7 |
| X | = | 189 |