| ( | 89 | ( | 1 | + | 20 100 | ) | ) | + | ( | 4 100 | x | ) | = | x |
| Left side of the equation = | 89 | ( | 1 | + | 20 100 | ) | + | ( | 4 100 | x | ) |
| = | 89 | × | 1 | + | 89 | × | 20 100 | + | ( | 4 100 | x | ) |
| = | 89 | + | 89 5 | + | ( | 4 100 | x | ) |
| = | 534 5 | + | ( | 4 100 | x | ) |
| = | 534 5 | + | 4 100 | x |
534 5 | + | 4 100 | x | = | x |
4 100 | x | − | x | = | - | 534 5 |
| - | 24 25 | x | = | - | 534 5 |
534 5 | = | 24 25 | x |
24 25 | x | = | 534 5 |
| x | = | 534 5 | ÷ | 24 25 |
| = | 534 5 | × | 25 24 |
| = | 89 | × | 5 4 |
| x | = | 445 4 |
| x | = | 111.25 |