3 100 | a | + | 7 200 | ( | 358386 | − | a | ) | = | 529929 50 |
| 方程左边 = | 3 100 | a | + | 7 200 | × | 358386 | − | 7 200 | a |
| = | 3 100 | a | + | 1254351 100 | − | 7 200 | a |
| = | - | 1 200 | a | + | 1254351 100 |
| - | 1 200 | a | + | 1254351 100 | = | 529929 50 |
| - | 1 200 | a | = | 529929 50 | − | 1254351 100 |
| - | 1 200 | a | = | - | 194493 100 |
194493 100 | = | 1 200 | a |
1 200 | a | = | 194493 100 |
| a | = | 194493 100 | ÷ | 1 200 |
| = | 194493 100 | × | 200 |
| = | 194493 | × | 2 |
| a | = | 388986 |