| - | 2020 | + | X | − | ( | X | × | 12 100 | ÷ | 12 | ) | = | 100 |
| Left side of the equation = | - | 2020 | + | X | − | X | × | 12 100 | ÷ | 12 |
| = | - | 2020 | + | X | − | X | × | 1 100 |
| = | - | 2020 | + | 99 100 | X |
| - | 2020 | + | 99 100 | X | = | 100 |
99 100 | X | = | 100 | + | 2020 |
99 100 | X | = | 2120 |
| X | = | 2120 | ÷ | 99 100 |
| = | 2120 | × | 100 99 |
| X | = | 212000 99 |
| X | = | 2141.414141 |