| 305 | + | x | = | 87 100 | ( | 357 | + | x | ) |
| Right side of the equation = | 87 100 | × | 357 | + | 87 100 | x |
| = | 31059 100 | + | 87 100 | x |
| 305 | + | x | = | 31059 100 | + | 87 100 | x |
| x | − | 87 100 | x | = | 31059 100 | − | 305 |
13 100 | x | = | 31059 100 | − | 305 |
13 100 | x | = | 559 100 |
| x | = | 559 100 | ÷ | 13 100 |
| = | 559 100 | × | 100 13 |
| = | 43 | × | 1 |
| x | = | 43 |