| ( | 100 | − | 71 | ) | ÷ | ( | 86 | − | 71 | ) | = | ( | x | − | 71 | ) | ÷ | ( | 100 | − | x | ) |
| Multiply both sides of the equation by: | ( | 86 | − | 71 | ) | , | ( | 100 | − | x | ) |
| ( | 100 | − | 71 | ) | ( | 100 | − | x | ) | = | ( | x | − | 71 | ) | ( | 86 | − | 71 | ) |
| 100 | ( | 100 | − | x | ) | − | 71 | ( | 100 | − | x | ) | = | ( | x | − | 71 | ) | ( | 86 | − | 71 | ) |
| 100 | ( | 100 | − | x | ) | − | 71 | ( | 100 | − | x | ) | = | x | ( | 86 | − | 71 | ) | − | 71 | ( | 86 | − | 71 | ) |
| 100 | × | 100 | − | 100 | x | − | 71 | ( | 100 | − | x | ) | = | x | ( | 86 | − | 71 | ) | − | 71 | ( | 86 | − | 71 | ) |
| 100 | × | 100 | − | 100 | x | − | 71 | ( | 100 | − | x | ) | = | x | × | 86 | − | x | × | 71 | − | 71 | ( | 86 | − | 71 | ) |
| 10000 | − | 100 | x | − | 71 | ( | 100 | − | x | ) | = | x | × | 86 | − | x | × | 71 | − | 71 | ( | 86 | − | 71 | ) |
| 10000 | − | 100 | x | − | 71 | ( | 100 | − | x | ) | = | 15 | x | − | 71 | ( | 86 | − | 71 | ) |
| 10000 | − | 100 | x | − | 71 | × | 100 | + | 71 | x | = | 15 | x | − | 71 | ( | 86 | − | 71 | ) |
| 10000 | − | 100 | x | − | 71 | × | 100 | + | 71 | x | = | 15 | x | − | 71 | × | 86 | + | 71 | × | 71 |
| 10000 | − | 100 | x | − | 7100 | + | 71 | x | = | 15 | x | − | 6106 | + | 5041 |
| 2900 | − | 29 | x | = | 15 | x | − | 1065 |
| - | 29 | x | − | 15 | x | = | - | 1065 | − | 2900 |
| - | 44 | x | = | - | 1065 | − | 2900 |
| - | 44 | x | = | - | 3965 |
| 3965 | = | 44 | x |
| 44 | x | = | 3965 |
| x | = | 3965 | ÷ | 44 |
| = | 3965 | × | 1 44 |
| x | = | 3965 44 |
| x | = | 90.113636 |