| ( | 6 5 | x | + | 23 20 | ( | 2200 | − | x | ) | ) | × | 9 10 | = | 2200 | + | 131 |
| Left side of the equation = | 6 5 | x | × | 9 10 | + | 23 20 | ( | 2200 | − | x | ) | × | 9 10 |
| = | 27 25 | x | + | 207 200 | ( | 2200 | − | x | ) |
| = | 27 25 | x | + | 207 200 | × | 2200 | − | 207 200 | x |
| = | 27 25 | x | + | 2277 | − | 207 200 | x |
| = | 9 200 | x | + | 2277 |
9 200 | x | + | 2277 | = | 2200 | + | 131 |
| Right side of the equation = | 2331 |
9 200 | x | + | 2277 | = | 2331 |
9 200 | x | = | 2331 | − | 2277 |
9 200 | x | = | 54 |
| x | = | 54 | ÷ | 9 200 |
| = | 54 | × | 200 9 |
| = | 6 | × | 200 |
| x | = | 1200 |