| 2 | ( | 15 | + | 4 | x | ) | − | 2 | ( | 12 | + | 4 | x | ) | + | 6 | ( | 23 | + | 8 | x | ) | = | 24 |
| 方程左边 = | 2 | × | 15 | + | 2 | × | 4 | x | − | 2 | ( | 12 | + | 4 | x | ) | + | 6 | ( | 23 | + | 8 | x | ) |
| = | 30 | + | 8 | x | − | 2 | ( | 12 | + | 4 | x | ) | + | 6 | ( | 23 | + | 8 | x | ) |
| = | 30 | + | 8 | x | − | 2 | × | 12 | − | 2 | × | 4 | x | + | 6 | ( | 23 | + | 8 | x | ) |
| = | 30 | + | 8 | x | − | 24 | − | 8 | x | + | 6 | ( | 23 | + | 8 | x | ) |
| = | 6 | + | 0 | x | + | 6 | ( | 23 | + | 8 | x | ) |
| = | 6 | + | 6 | × | 23 | + | 6 | × | 8 | x |
| = | 6 | + | 138 | + | 48 | x |
| = | 144 | + | 48 | x |
| 144 | + | 48 | x | = | 24 |
| 48 | x | = | 24 | − | 144 |
| 48 | x | = | - | 120 |
| x | = | - | 120 | ÷ | 48 |
| = | - | 120 | × | 1 48 |
| = | - | 5 | × | 1 2 |
| x | = | - | 5 2 |
| x | = | - 2.5 |