| ( | 1 | + | x | ) | × | 30 | ( | 6000 | ) | = | 20000 |
| Left side of the equation = | 1 | × | 30 | ( | 6000 | ) | + | x | × | 30 | ( | 6000 | ) |
| = | 30 | ( | 6000 | ) | + | x | × | 30 | ( | 6000 | ) |
| = | 30 | × | 6000 | + | x | × | 30 | ( | 6000 | ) |
| = | 180000 | + | x | × | 30 | ( | 6000 | ) |
| = | 180000 | + | x | × | 30 | × | 6000 |
| = | 180000 | + | x | × | 180000 |
| 180000 | + | 180000 | x | = | 20000 |
| 180000 | x | = | 20000 | − | 180000 |
| 180000 | x | = | - | 160000 |
| x | = | - | 160000 | ÷ | 180000 |
| = | - | 160000 | × | 1 180000 |
| = | - | 8 | × | 1 9 |
| x | = | - | 8 9 |
| x | = | - 0.888889 |