13 5 | x | + | ( | 23 | − | 10 | − | x | ) | × | 7 2 | + | ( | 23 | − | 10 | − | x | ) | × | 13 5 | = | 409 5 |
| Left side of the equation = | 13 5 | x | + | 23 | × | 7 2 | − | 10 | × | 7 2 | − | x | × | 7 2 | + | ( | 23 | − | 10 | − | x | ) | × | 13 5 |
| = | 13 5 | x | + | 161 2 | − | 35 | − | x | × | 7 2 | + | ( | 23 | − | 10 | − | x | ) | × | 13 5 |
| = | - | 9 10 | x | + | 91 2 | + | ( | 23 | − | 10 | − | x | ) | × | 13 5 |
| = | - | 9 10 | x | + | 91 2 | + | 23 | × | 13 5 | − | 10 | × | 13 5 | − | x | × | 13 5 |
| = | - | 9 10 | x | + | 91 2 | + | 299 5 | − | 26 | − | x | × | 13 5 |
| = | - | 7 2 | x | + | 793 10 |
| - | 7 2 | x | + | 793 10 | = | 409 5 |
| - | 7 2 | x | = | 409 5 | − | 793 10 |
| - | 7 2 | x | = | 5 2 |
| - | 5 2 | = | 7 2 | x |
7 2 | x | = | - | 5 2 |
| x | = | - | 5 2 | ÷ | 7 2 |
| = | - | 5 2 | × | 2 7 |
| = | - | 5 | × | 1 7 |
| x | = | - | 5 7 |
| x | = | - 0.714286 |