| ( | 70000 | + | 80000 | x | ) | = | 64 | ÷ | 81 | × | ( | 160000 | − | 10000 | x | ) |
| 方程左边 = | 70000 | + | 80000 | x |
| 70000 | + | 80000 | x | = | 64 | ÷ | 81 | × | ( | 160000 | − | 10000 | x | ) |
| 方程右边 = | 64 81 | ( | 160000 | − | 10000 | x | ) |
| 70000 | + | 80000 | x | = | 64 81 | ( | 160000 | − | 10000 | x | ) |
| 方程右边 = | 64 81 | × | 160000 | − | 64 81 | × | 10000 | x |
| = | 10240000 81 | − | 640000 81 | x |
| 70000 | + | 80000 | x | = | 10240000 81 | − | 640000 81 | x |
| 80000 | x | + | 640000 81 | x | = | 10240000 81 | − | 70000 |
7120000 81 | x | = | 10240000 81 | − | 70000 |
7120000 81 | x | = | 4570000 81 |
| x | = | 4570000 81 | ÷ | 7120000 81 |
| = | 4570000 81 | × | 81 7120000 |
| = | 457 | × | 1 712 |
| x | = | 457 712 |
| x | = | 0.641854 |