| x | × | 1 | + | x | × | 2 | + | x | × | 3 | = | 4 |
| 方程左边 = | 6 | x |
| 6 | x | = | 4 |
| x | = | 4 | ÷ | 6 |
| = | 4 | × | 1 6 |
| = | 2 | × | 1 3 |
| x | = | 2 3 |
| x | = | 0.666667 |
| x | × | 1 | − | 2 | x | × | 2 | + | x | × | 3 | + | x | × | 4 | = | 3 |
| 方程左边 = | x | × | 1 | − | 4 | x | + | x | × | 3 | + | x | × | 4 |
| = | 4 | x |
| 4 | x | = | 3 |
| x | = | 3 | ÷ | 4 |
| = | 3 | × | 1 4 |
| x | = | 3 4 |
| x | = | 0.75 |
| 2 | x | − | 3 | x | × | 2 | + | 3 | x | × | 3 | + | 5 | x | × | 4 | = | 5 |
| 方程左边 = | 2 | x | − | 6 | x | + | 9 | x | + | 20 | x |
| = | 25 | x |
| 25 | x | = | 5 |
| x | = | 5 | ÷ | 25 |
| = | 5 | × | 1 25 |
| = | 1 | × | 1 5 |
| x | = | 1 5 |
| x | = | 0.2 |