| 15 | + | ( | x | × | 21 20 | + | 5 | ) | + | 0 | + | ( | 15 | × | 331 2000 | ) | = | 1761 50 |
| Left side of the equation = | 15 | + | ( | x | × | 21 20 | + | 5 | ) | + | ( | 15 | × | 331 2000 | ) |
| 15 | + | ( | x | × | 21 20 | + | 5 | ) | + | ( | 15 | × | 331 2000 | ) | = | 1761 50 |
| Left side of the equation = | 15 | + | x | × | 21 20 | + | 5 | + | ( | 15 | × | 331 2000 | ) |
| = | 20 | + | 21 20 | x | + | ( | 15 | × | 331 2000 | ) |
| = | 20 | + | 21 20 | x | + | 15 | × | 331 2000 |
| = | 20 | + | 21 20 | x | + | 993 400 |
| = | 8993 400 | + | 21 20 | x |
8993 400 | + | 21 20 | x | = | 1761 50 |
21 20 | x | = | 1761 50 | − | 8993 400 |
21 20 | x | = | 1019 80 |
| x | = | 1019 80 | ÷ | 21 20 |
| = | 1019 80 | × | 20 21 |
| = | 1019 4 | × | 1 21 |
| x | = | 1019 84 |
| x | = | 12.130952 |