| ( | X | + | 450 | ) | × | 1200 | = | 203 25 |
| Left side of the equation = | X | × | 1200 | + | 450 | × | 1200 |
| = | X | × | 1200 | + | 540000 |
| 1200 | X | + | 540000 | = | 203 25 |
| 1200 | X | = | 203 25 | − | 540000 |
| 1200 | X | = | - | 13499797 25 |
| X | = | - | 13499797 25 | ÷ | 1200 |
| = | - | 13499797 25 | × | 1 1200 |
| X | = | - | 13499797 30000 |
| X | = | - 449.993233 |