| ( | X | + | 801 100 | + | 202 25 | + | 403 50 | ) | ÷ | 4 | = | X |
| 方程左边 = | X | × | 1 4 | + | 801 100 | × | 1 4 | + | 202 25 | × | 1 4 | + | 403 50 | × | 1 4 |
| = | X | × | 1 4 | + | 801 400 | + | 101 50 | + | 403 200 |
| = | 1 4 | X | + | 483 80 |
1 4 | X | + | 483 80 | = | X |
1 4 | X | − | X | = | - | 483 80 |
| - | 3 4 | X | = | - | 483 80 |
483 80 | = | 3 4 | X |
3 4 | X | = | 483 80 |
| X | = | 483 80 | ÷ | 3 4 |
| = | 483 80 | × | 4 3 |
| = | 161 20 | × | 1 |
| X | = | 161 20 |
| X | = | 8.05 |