| a | = | ( | a | − | ( | a | × | 1 4 | ) | ) | + | ( | ( | a | × | 1 4 | ) | × | 3 50 | ) |
| 方程右边 = | a | − | ( | a | × | 1 4 | ) | + | ( | ( | a | × | 1 4 | ) | × | 3 50 | ) |
| = | a | − | a | × | 1 4 | + | ( | ( | a | × | 1 4 | ) | × | 3 50 | ) |
| = | 3 4 | a | + | ( | ( | a | × | 1 4 | ) | × | 3 50 | ) |
| = | 3 4 | a | + | ( | a | × | 1 4 | ) | × | 3 50 |
| = | 3 4 | a | + | a | × | 1 4 | × | 3 50 |
| = | 3 4 | a | + | a | × | 3 200 |
| = | 153 200 | a |
| a | = | 153 200 | a |
| a | − | 153 200 | a | = | 0 |
47 200 | a | = | 0 |
| a | = | 0 | ÷ | 47 200 |
| = | 0 | × | 200 47 |
| a | = | 0 |