| ( | 13 10 | + | ( | 250 | − | x | ) | × | 6 5 | ) | × | 7 10 | = | 250 | + | 67 2 |
| 方程左边 = | 13 10 | × | 7 10 | + | ( | 250 | − | x | ) | × | 6 5 | × | 7 10 |
| = | 91 100 | + | ( | 250 | − | x | ) | × | 21 25 |
| = | 91 100 | + | 250 | × | 21 25 | − | x | × | 21 25 |
| = | 91 100 | + | 210 | − | x | × | 21 25 |
| = | 21091 100 | − | 21 25 | x |
21091 100 | − | 21 25 | x | = | 250 | + | 67 2 |
| 方程右边 = | 567 2 |
21091 100 | − | 21 25 | x | = | 567 2 |
| - | 21 25 | x | = | 567 2 | − | 21091 100 |
| - | 21 25 | x | = | 7259 100 |
| - | 7259 100 | = | 21 25 | x |
21 25 | x | = | - | 7259 100 |
| x | = | - | 7259 100 | ÷ | 21 25 |
| = | - | 7259 100 | × | 25 21 |
| = | - | 1037 4 | × | 1 3 |
| x | = | - | 1037 12 |
| x | = | - 86.416667 |