| ( | 290 | ( | 1 | + | 20 100 | ) | ) | + | ( | 7 100 | x | ) | = | x |
| Left side of the equation = | 290 | ( | 1 | + | 20 100 | ) | + | ( | 7 100 | x | ) |
| = | 290 | × | 1 | + | 290 | × | 20 100 | + | ( | 7 100 | x | ) |
| = | 290 | + | 58 | + | ( | 7 100 | x | ) |
| = | 348 | + | ( | 7 100 | x | ) |
| = | 348 | + | 7 100 | x |
| 348 | + | 7 100 | x | = | x |
7 100 | x | − | x | = | - | 348 |
| - | 93 100 | x | = | - | 348 |
| 348 | = | 93 100 | x |
93 100 | x | = | 348 |
| x | = | 348 | ÷ | 93 100 |
| = | 348 | × | 100 93 |
| = | 116 | × | 100 31 |
| x | = | 11600 31 |
| x | = | 374.193548 |