| ( | 81 5 | ( | 1 | + | 20 100 | ) | ) | + | ( | 3 100 | x | ) | = | x |
| Left side of the equation = | 81 5 | ( | 1 | + | 20 100 | ) | + | ( | 3 100 | x | ) |
| = | 81 5 | × | 1 | + | 81 5 | × | 20 100 | + | ( | 3 100 | x | ) |
| = | 81 5 | + | 81 25 | + | ( | 3 100 | x | ) |
| = | 486 25 | + | ( | 3 100 | x | ) |
| = | 486 25 | + | 3 100 | x |
486 25 | + | 3 100 | x | = | x |
3 100 | x | − | x | = | - | 486 25 |
| - | 97 100 | x | = | - | 486 25 |
486 25 | = | 97 100 | x |
97 100 | x | = | 486 25 |
| x | = | 486 25 | ÷ | 97 100 |
| = | 486 25 | × | 100 97 |
| = | 486 | × | 4 97 |
| x | = | 1944 97 |
| x | = | 20.041237 |