3 2 | + | 7 100 | × | 50 | + | x | × | 200 | = | 3 2 | + | 7 100 | × | 12 | + | 7 200 | × | 200 |
| 方程左边 = | 3 2 | + | 7 2 | + | x | × | 200 |
| = | 5 | + | 200 | x |
| 5 | + | 200 | x | = | 3 2 | + | 7 100 | × | 12 | + | 7 200 | × | 200 |
| 方程右边 = | 3 2 | + | 21 25 | + | 7 |
| = | 467 50 |
| 5 | + | 200 | x | = | 467 50 |
| 200 | x | = | 467 50 | − | 5 |
| 200 | x | = | 217 50 |
| x | = | 217 50 | ÷ | 200 |
| = | 217 50 | × | 1 200 |
| x | = | 217 10000 |
| x | = | 0.0217 |