| 5 | ( | 1 | + | X | ) | + | 4 | × | 1 | + | 1 | × | 1 | = | 49 10 | ( | X | + | 3 | ) |
| 方程左边 = | 5 | ( | 1 | + | X | ) | + | 4 | + | 1 |
| = | 5 | ( | 1 | + | X | ) | + | 5 |
| 5 | ( | 1 | + | X | ) | + | 5 | = | 49 10 | ( | X | + | 3 | ) |
| 方程左边 = | 5 | × | 1 | + | 5 | X | + | 5 |
| = | 5 | + | 5 | X | + | 5 |
| = | 10 | + | 5 | X |
| 10 | + | 5 | X | = | 49 10 | ( | X | + | 3 | ) |
| 方程右边 = | 49 10 | X | + | 49 10 | × | 3 |
| = | 49 10 | X | + | 147 10 |
| 10 | + | 5 | X | = | 49 10 | X | + | 147 10 |
| 5 | X | − | 49 10 | X | = | 147 10 | − | 10 |
1 10 | X | = | 147 10 | − | 10 |
1 10 | X | = | 47 10 |
| X | = | 47 10 | ÷ | 1 10 |
| = | 47 10 | × | 10 |
| = | 47 | × | 1 |
| X | = | 47 |