| ( | 200 | + | x | ) | ÷ | ( | 228 | + | x | ) | = | 99 100 |
| Multiply both sides of the equation by: | ( | 228 | + | x | ) |
| ( | 200 | + | x | ) | = | 99 100 | ( | 228 | + | x | ) |
| 200 | + | x | = | 99 100 | ( | 228 | + | x | ) |
| 200 | + | x | = | 99 100 | × | 228 | + | 99 100 | x |
| 200 | + | x | = | 5643 25 | + | 99 100 | x |
| x | − | 99 100 | x | = | 5643 25 | − | 200 |
1 100 | x | = | 5643 25 | − | 200 |
1 100 | x | = | 643 25 |
| x | = | 643 25 | ÷ | 1 100 |
| = | 643 25 | × | 100 |
| = | 643 | × | 4 |
| x | = | 2572 |