| - | 4 | ( | 13 | + | 5 | x | ) | + | 7 | = | - | 11 | + | 2 | ( | 13 | + | 5 | x | ) |
| Left side of the equation = | - | 4 | × | 13 | − | 4 | × | 5 | x | + | 7 |
| = | - | 52 | − | 20 | x | + | 7 |
| = | - | 45 | − | 20 | x |
| - | 45 | − | 20 | x | = | - | 11 | + | 2 | ( | 13 | + | 5 | x | ) |
| Right side of the equation = | - | 11 | + | 2 | × | 13 | + | 2 | × | 5 | x |
| = | - | 11 | + | 26 | + | 10 | x |
| = | 15 | + | 10 | x |
| - | 45 | − | 20 | x | = | 15 | + | 10 | x |
| - | 20 | x | − | 10 | x | = | 15 | + | 45 |
| - | 30 | x | = | 15 | + | 45 |
| - | 30 | x | = | 60 |
| - | 60 | = | 30 | x |
| 30 | x | = | - | 60 |
| x | = | - | 60 | ÷ | 30 |
| = | - | 60 | × | 1 30 |
| = | - | 2 | × | 1 |
| x | = | - | 2 |