| 150 | ( | - | 6 | + | x | ) | + | 120 | ( | 12 | − | x | ) | + | 210 | ( | - | 3 | + | x | ) | − | 150 | ( | 9 | − | x | ) | = | 730 |
| Left side of the equation = | - | 150 | × | 6 | + | 150 | x | + | 120 | ( | 12 | − | x | ) | + | 210 | ( | - | 3 | + | x | ) | − | 150 | ( | 9 | − | x | ) |
| = | - | 900 | + | 150 | x | + | 120 | ( | 12 | − | x | ) | + | 210 | ( | - | 3 | + | x | ) | − | 150 | ( | 9 | − | x | ) |
| = | - | 900 | + | 150 | x | + | 120 | × | 12 | − | 120 | x | + | 210 | ( | - | 3 | + | x | ) | − | 150 | ( | 9 | − | x | ) |
| = | - | 900 | + | 150 | x | + | 1440 | − | 120 | x | + | 210 | ( | - | 3 | + | x | ) | − | 150 | ( | 9 | − | x | ) |
| = | 540 | + | 30 | x | + | 210 | ( | - | 3 | + | x | ) | − | 150 | ( | 9 | − | x | ) |
| = | 540 | + | 30 | x | − | 210 | × | 3 | + | 210 | x | − | 150 | ( | 9 | − | x | ) |
| = | 540 | + | 30 | x | − | 630 | + | 210 | x | − | 150 | ( | 9 | − | x | ) |
| = | - | 90 | + | 240 | x | − | 150 | ( | 9 | − | x | ) |
| = | - | 90 | + | 240 | x | − | 150 | × | 9 | + | 150 | x |
| = | - | 90 | + | 240 | x | − | 1350 | + | 150 | x |
| = | - | 1440 | + | 390 | x |
| - | 1440 | + | 390 | x | = | 730 |
| 390 | x | = | 730 | + | 1440 |
| 390 | x | = | 2170 |
| x | = | 2170 | ÷ | 390 |
| = | 2170 | × | 1 390 |
| = | 217 | × | 1 39 |
| x | = | 217 39 |
| x | = | 5.564103 |