| ( | 300 | × | 20 100 | + | x | ) | ÷ | ( | 300 | + | x | ) | = | 25 100 |
| Multiply both sides of the equation by: | ( | 300 | + | x | ) |
| ( | 300 | × | 20 100 | + | x | ) | = | 25 100 | ( | 300 | + | x | ) |
| 300 | × | 20 100 | + | x | = | 25 100 | ( | 300 | + | x | ) |
| 300 | × | 20 100 | + | x | = | 25 100 | × | 300 | + | 25 100 | x |
| 60 | + | x | = | 75 | + | 25 100 | x |
| x | − | 25 100 | x | = | 75 | − | 60 |
3 4 | x | = | 75 | − | 60 |
3 4 | x | = | 15 |
| x | = | 15 | ÷ | 3 4 |
| = | 15 | × | 4 3 |
| = | 5 | × | 4 |
| x | = | 20 |