| ( | X | − | 300 | ) | ( | 1 | − | 40 100 | ) | ÷ | 1000 | = | ( | ( | X | − | 300 | ) | ( | 1 | − | 40 100 | ) | − | 4000 | × | 12 100 | ) | ÷ | 800 |
| Left side of the equation = | X | ( | 1 | − | 40 100 | ) | × | 1 1000 | − | 300 | ( | 1 | − | 40 100 | ) | × | 1 1000 |
| = | X | ( | 1 | − | 40 100 | ) | × | 1 1000 | − | 3 10 | ( | 1 | − | 40 100 | ) |
| = | X | × | 1 | × | 1 1000 | − | X | × | 40 100 | × | 1 1000 | − | 3 10 | ( | 1 | − | 40 100 | ) |
| = | X | × | 1 1000 | − | X | × | 1 2500 | − | 3 10 | ( | 1 | − | 40 100 | ) |
| = | 3 5000 | X | − | 3 10 | ( | 1 | − | 40 100 | ) |
| = | 3 5000 | X | − | 3 10 | × | 1 | + | 3 10 | × | 40 100 |
| = | 3 5000 | X | − | 3 10 | + | 3 25 |
| = | 3 5000 | X | − | 9 50 |
3 5000 | X | − | 9 50 | = | ( | ( | X | − | 300 | ) | ( | 1 | − | 40 100 | ) | − | 4000 | × | 12 100 | ) | ÷ | 800 |
| Right side of the equation = | ( | X | − | 300 | ) | ( | 1 | − | 40 100 | ) | × | 1 800 | − | 4000 | × | 12 100 | × | 1 800 |
| = | ( | X | − | 300 | ) | ( | 1 | − | 40 100 | ) | × | 1 800 | − | 3 5 |
| = | X | ( | 1 | − | 40 100 | ) | × | 1 800 | − | 300 | ( | 1 | − | 40 100 | ) | × | 1 800 | − | 3 5 |
| = | X | ( | 1 | − | 40 100 | ) | × | 1 800 | − | 3 8 | ( | 1 | − | 40 100 | ) | − | 3 5 |
| = | X | × | 1 | × | 1 800 | − | X | × | 40 100 | × | 1 800 | − | 3 8 | ( | 1 | − | 40 100 | ) | − | 3 5 |
| = | X | × | 1 800 | − | X | × | 1 2000 | − | 3 8 | ( | 1 | − | 40 100 | ) | − | 3 5 |
| = | 3 4000 | X | − | 3 8 | ( | 1 | − | 40 100 | ) | − | 3 5 |
| = | 3 4000 | X | − | 3 8 | × | 1 | + | 3 8 | × | 40 100 | − | 3 5 |
| = | 3 4000 | X | − | 3 8 | + | 3 20 | − | 3 5 |
| = | 3 4000 | X | − | 33 40 |
3 5000 | X | − | 9 50 | = | 3 4000 | X | − | 33 40 |
3 5000 | X | − | 3 4000 | X | = | - | 33 40 | + | 9 50 |
| - | 3 20000 | X | = | - | 33 40 | + | 9 50 |
| - | 3 20000 | X | = | - | 129 200 |
129 200 | = | 3 20000 | X |
3 20000 | X | = | 129 200 |
| X | = | 129 200 | ÷ | 3 20000 |
| = | 129 200 | × | 20000 3 |
| = | 43 | × | 100 |
| X | = | 4300 |