| ( | 190 | + | 210 | ) | ÷ | V | − | ( | 190 | + | 210 | ) | × | 5 4 | V | = | 1 |
| 方程两边同时乘以: | V |
| ( | 190 | + | 210 | ) | − | ( | 190 | + | 210 | ) | × | 5 4 | V | V | = | 1 | V |
| 190 | + | 210 | − | ( | 190 | + | 210 | ) | × | 5 4 | V | V | = | 1 | V |
| 400 | − | ( | 190 | + | 210 | ) | × | 5 4 | V | V | = | 1 | V |
| 400 | − | 190 | × | 5 4 | V | V | − | 210 | × | 5 4 | V | V | = | 1 | V |
| 400 | − | 475 2 | V | V | − | 525 2 | V | V | = | 1 | V |