- | 6 | ( | 2 | r | + | 8 | ) | = | - | 10 | ( | r | − | 3 | ) |
方程左边 = | - | 6 | × | 2 | r | − | 6 | × | 8 |
= | - | 12 | r | − | 48 |
- | 12 | r | − | 48 | = | - | 10 | ( | r | − | 3 | ) |
方程右边 = | - | 10 | r | + | 10 | × | 3 |
= | - | 10 | r | + | 30 |
- | 12 | r | − | 48 | = | - | 10 | r | + | 30 |
- | 12 | r | + | 10 | r | = | 30 | + | 48 |
- | 2 | r | = | 30 | + | 48 |
- | 2 | r | = | 78 |
- | 78 | = | 2 | r |
2 | r | = | - | 78 |
r | = | - | 78 | ÷ | 2 |
= | - | 78 | × | 1 2 |
= | - | 39 | × | 1 |
r | = | - | 39 |