| 367 | − | 4 | ( | 10 | x | + | 120 | ) | = | 549 | − | 7 | ( | 7 | x | + | 74 | ) |
| Left side of the equation = | 367 | − | 4 | × | 10 | x | − | 4 | × | 120 |
| = | 367 | − | 40 | x | − | 480 |
| = | - | 113 | − | 40 | x |
| - | 113 | − | 40 | x | = | 549 | − | 7 | ( | 7 | x | + | 74 | ) |
| Right side of the equation = | 549 | − | 7 | × | 7 | x | − | 7 | × | 74 |
| = | 549 | − | 49 | x | − | 518 |
| = | 31 | − | 49 | x |
| - | 113 | − | 40 | x | = | 31 | − | 49 | x |
| - | 40 | x | + | 49 | x | = | 31 | + | 113 |
| 9 | x | = | 31 | + | 113 |
| 9 | x | = | 144 |
| x | = | 144 | ÷ | 9 |
| = | 144 | × | 1 9 |
| = | 16 | × | 1 |
| x | = | 16 |