| ( | x | + | 2000 | ) | × | 21 10 | = | ( | x | + | 1607 | ) | × | 11 5 |
| 方程左边 = | x | × | 21 10 | + | 2000 | × | 21 10 |
| = | x | × | 21 10 | + | 4200 |
21 10 | x | + | 4200 | = | ( | x | + | 1607 | ) | × | 11 5 |
| 方程右边 = | x | × | 11 5 | + | 1607 | × | 11 5 |
| = | x | × | 11 5 | + | 17677 5 |
21 10 | x | + | 4200 | = | 11 5 | x | + | 17677 5 |
21 10 | x | − | 11 5 | x | = | 17677 5 | − | 4200 |
| - | 1 10 | x | = | 17677 5 | − | 4200 |
| - | 1 10 | x | = | - | 3323 5 |
3323 5 | = | 1 10 | x |
1 10 | x | = | 3323 5 |
| x | = | 3323 5 | ÷ | 1 10 |
| = | 3323 5 | × | 10 |
| = | 3323 | × | 2 |
| x | = | 6646 |