18 100 | x | = | 18 100 | x | + | 15 100 | ( | 1 | − | x | ) |
| Right side of the equation = | 18 100 | x | + | 15 100 | × | 1 | − | 15 100 | x |
| = | 18 100 | x | + | 3 20 | − | 15 100 | x |
| = | 3 100 | x | + | 3 20 |
18 100 | x | = | 3 100 | x | + | 3 20 |
18 100 | x | − | 3 100 | x | = | 3 20 |
3 20 | x | = | 3 20 |
| x | = | 3 20 | ÷ | 3 20 |
| = | 3 20 | × | 20 3 |
| = | 1 | × | 1 |
| x | = | 1 |