| ( | 19 10 | − | X | ) | × | 100 | = | ( | 490 | − | 150 | ) | ÷ | 12 |
| Left side of the equation = | 19 10 | × | 100 | − | X | × | 100 |
| = | 190 | − | X | × | 100 |
| 190 | − | 100 | X | = | ( | 490 | − | 150 | ) | ÷ | 12 |
| Right side of the equation = | 490 | × | 1 12 | − | 150 | × | 1 12 |
| = | 245 6 | − | 25 2 |
| = | 85 3 |
| 190 | − | 100 | X | = | 85 3 |
| - | 100 | X | = | 85 3 | − | 190 |
| - | 100 | X | = | - | 485 3 |
485 3 | = | 100 | X |
| 100 | X | = | 485 3 |
| X | = | 485 3 | ÷ | 100 |
| = | 485 3 | × | 1 100 |
| = | 97 3 | × | 1 20 |
| X | = | 97 60 |
| X | = | 1.616667 |