1 2 | x | + | ( | 1 | + | 1 5 | ) | ( | 120 | − | x | ) | = | 66 |
| Left side of the equation = | 1 2 | x | + | 1 | ( | 120 | − | x | ) | + | 1 5 | ( | 120 | − | x | ) |
| = | 1 2 | x | + | 1 | × | 120 | − | 1 | x | + | 1 5 | ( | 120 | − | x | ) |
| = | 1 2 | x | + | 120 | − | 1 | x | + | 1 5 | ( | 120 | − | x | ) |
| = | - | 1 2 | x | + | 120 | + | 1 5 | ( | 120 | − | x | ) |
| = | - | 1 2 | x | + | 120 | + | 1 5 | × | 120 | − | 1 5 | x |
| = | - | 1 2 | x | + | 120 | + | 24 | − | 1 5 | x |
| = | - | 7 10 | x | + | 144 |
| - | 7 10 | x | + | 144 | = | 66 |
| - | 7 10 | x | = | 66 | − | 144 |
| - | 7 10 | x | = | - | 78 |
| 78 | = | 7 10 | x |
7 10 | x | = | 78 |
| x | = | 78 | ÷ | 7 10 |
| = | 78 | × | 10 7 |
| x | = | 780 7 |
| x | = | 111.428571 |