| 13 | ÷ | 25 | × | X | + | 2 | ( | 7 25 | X | × | 8 | + | 7 | ÷ | 5 | × | X | ) | = | 79 | − | 40 |
| Left side of the equation = | 13 25 | X | + | 2 | ( | 7 25 | X | × | 8 | + | 7 | ÷ | 5 | × | X | ) |
13 25 | X | + | 2 | ( | 7 25 | X | × | 8 | + | 7 | ÷ | 5 | × | X | ) | = | 79 | − | 40 |
| Left side of the equation = | 13 25 | X | + | 2 | × | 7 25 | X | × | 8 | + | 2 | × | 7 | ÷ | 5 | × | X |
| = | 13 25 | X | + | 112 25 | X | + | 14 5 | X |
| = | 39 5 | X |
39 5 | X | = | 79 | − | 40 |
| Right side of the equation = | 39 |
39 5 | X | = | 39 |
| X | = | 39 | ÷ | 39 5 |
| = | 39 | × | 5 39 |
| = | 1 | × | 5 |
| X | = | 5 |