| x | = | ( | 100 | + | x | ) | ( | 13 100 | − | 9 100 | ) |
| Right side of the equation = | 100 | ( | 13 100 | − | 9 100 | ) | + | x | ( | 13 100 | − | 9 100 | ) |
| = | 100 | × | 13 100 | − | 100 | × | 9 100 | + | x | ( | 13 100 | − | 9 100 | ) |
| = | 13 | − | 9 | + | x | ( | 13 100 | − | 9 100 | ) |
| = | 4 | + | x | ( | 13 100 | − | 9 100 | ) |
| = | 4 | + | x | × | 13 100 | − | x | × | 9 100 |
| = | 4 | + | 1 25 | x |
| x | = | 4 | + | 1 25 | x |
| x | − | 1 25 | x | = | 4 |
24 25 | x | = | 4 |
| x | = | 4 | ÷ | 24 25 |
| = | 4 | × | 25 24 |
| = | 1 | × | 25 6 |
| x | = | 25 6 |
| x | = | 4.166667 |