| x | ÷ | 71 2 | + | ( | 151 5 | − | x | ) | ÷ | 80 | = | 117 5 | ÷ | 39 |
| 方程左边 = | 2 71 | x | + | 151 5 | × | 1 80 | − | x | × | 1 80 |
| = | 2 71 | x | + | 151 400 | − | x | × | 1 80 |
| = | 89 5680 | x | + | 151 400 |
89 5680 | x | + | 151 400 | = | 117 5 | ÷ | 39 |
| 方程右边 = | 3 5 |
89 5680 | x | + | 151 400 | = | 3 5 |
89 5680 | x | = | 3 5 | − | 151 400 |
89 5680 | x | = | 89 400 |
| x | = | 89 400 | ÷ | 89 5680 |
| = | 89 400 | × | 5680 89 |
| = | 1 5 | × | 71 |
| x | = | 71 5 |
| x | = | 14.2 |