| 90 | x | ( | 1 | − | 30 100 | ) | + | 100 | ( | 2 | x | − | 1 | ) | ( | 1 | − | 15 100 | ) | = | ( | 90 | x | + | 100 | ( | 2 | x | − | 1 | ) | ) | ( | 1 | − | 20 100 | ) |
| Left side of the equation = | 90 | x | × | 1 | − | 90 | x | × | 30 100 | + | 100 | ( | 2 | x | − | 1 | ) | ( | 1 | − | 15 100 | ) |
| = | 90 | x | − | 27 | x | + | 100 | ( | 2 | x | − | 1 | ) | ( | 1 | − | 15 100 | ) |
| = | 63 | x | + | 100 | ( | 2 | x | − | 1 | ) | ( | 1 | − | 15 100 | ) |
| = | 63 | x | + | 100 | × | 2 | x | ( | 1 | − | 15 100 | ) | − | 100 | × | 1 | ( | 1 | − | 15 100 | ) |
| = | 63 | x | + | 200 | x | ( | 1 | − | 15 100 | ) | − | 100 | ( | 1 | − | 15 100 | ) |
| = | 63 | x | + | 200 | x | × | 1 | − | 200 | x | × | 15 100 | − | 100 | ( | 1 | − | 15 100 | ) |
| = | 63 | x | + | 200 | x | − | 30 | x | − | 100 | ( | 1 | − | 15 100 | ) |
| = | 233 | x | − | 100 | ( | 1 | − | 15 100 | ) |
| = | 233 | x | − | 100 | × | 1 | + | 100 | × | 15 100 |
| = | 233 | x | − | 100 | + | 15 |
| = | 233 | x | − | 85 |
| 233 | x | − | 85 | = | ( | 90 | x | + | 100 | ( | 2 | x | − | 1 | ) | ) | ( | 1 | − | 20 100 | ) |
| Right side of the equation = | 90 | x | ( | 1 | − | 20 100 | ) | + | 100 | ( | 2 | x | − | 1 | ) | ( | 1 | − | 20 100 | ) |
| = | 90 | x | × | 1 | − | 90 | x | × | 20 100 | + | 100 | ( | 2 | x | − | 1 | ) | ( | 1 | − | 20 100 | ) |
| = | 90 | x | − | 18 | x | + | 100 | ( | 2 | x | − | 1 | ) | ( | 1 | − | 20 100 | ) |
| = | 72 | x | + | 100 | ( | 2 | x | − | 1 | ) | ( | 1 | − | 20 100 | ) |
| = | 72 | x | + | 100 | × | 2 | x | ( | 1 | − | 20 100 | ) | − | 100 | × | 1 | ( | 1 | − | 20 100 | ) |
| = | 72 | x | + | 200 | x | ( | 1 | − | 20 100 | ) | − | 100 | ( | 1 | − | 20 100 | ) |
| = | 72 | x | + | 200 | x | × | 1 | − | 200 | x | × | 20 100 | − | 100 | ( | 1 | − | 20 100 | ) |
| = | 72 | x | + | 200 | x | − | 40 | x | − | 100 | ( | 1 | − | 20 100 | ) |
| = | 232 | x | − | 100 | ( | 1 | − | 20 100 | ) |
| = | 232 | x | − | 100 | × | 1 | + | 100 | × | 20 100 |
| = | 232 | x | − | 100 | + | 20 |
| = | 232 | x | − | 80 |
| 233 | x | − | 85 | = | 232 | x | − | 80 |
| 233 | x | − | 85 | = | 232 | x | − | 80 |
| 233 | x | − | 232 | x | = | - | 80 | + | 85 |
| x | = | - | 80 | + | 85 |
| x | = | - | 80 | + | 85 |
| x | = | 5 |