| ( | 13000 | + | x | + | 3 50 | x | ) | × | 13 100 | + | 13000 | + | x | + | 3 50 | x | = | 18740 |
| Left side of the equation = | ( | 13000 | + | x | + | 3 50 | x | ) | × | 13 100 | + | 13000 | + | 53 50 | x |
| ( | 13000 | + | x | + | 3 50 | x | ) | × | 13 100 | + | 13000 | + | 53 50 | x | = | 18740 |
| Left side of the equation = | 13000 | × | 13 100 | + | x | × | 13 100 | + | 3 50 | x | × | 13 100 | + | 13000 | + | 53 50 | x |
| = | 1690 | + | x | × | 13 100 | + | 39 5000 | x | + | 13000 | + | 53 50 | x |
| = | 14690 | + | 5989 5000 | x |
| 14690 | + | 5989 5000 | x | = | 18740 |
5989 5000 | x | = | 18740 | − | 14690 |
5989 5000 | x | = | 4050 |
| x | = | 4050 | ÷ | 5989 5000 |
| = | 4050 | × | 5000 5989 |
| x | = | 20250000 5989 |
| x | = | 3381.198865 |