9 100 | = | 5 100 | + | X | ( | 10 100 | − | 5 100 | ) |
| Right side of the equation = | 5 100 | + | X | × | 10 100 | − | X | × | 5 100 |
| = | 5 100 | + | 1 20 | X |
9 100 | = | 5 100 | + | 1 20 | X |
| - | 1 20 | X | = | 5 100 | − | 9 100 |
| - | 1 20 | X | = | - | 1 25 |
1 25 | = | 1 20 | X |
1 20 | X | = | 1 25 |
| X | = | 1 25 | ÷ | 1 20 |
| = | 1 25 | × | 20 |
| = | 1 5 | × | 4 |
| X | = | 4 5 |
| X | = | 0.8 |