| b | = | ( | 30 | ÷ | 7 | ) | + | ( | 8 | b | ÷ | 7 | ) |
| Right side of the equation = | 30 | ÷ | 7 | + | ( | 8 | b | ÷ | 7 | ) |
| = | 30 7 | + | ( | 8 | b | ÷ | 7 | ) |
| = | 30 7 | + | 8 | b | ÷ | 7 |
| = | 30 7 | + | 8 7 | b |
| b | = | 30 7 | + | 8 7 | b |
| b | − | 8 7 | b | = | 30 7 |
| - | 1 7 | b | = | 30 7 |
| - | 30 7 | = | 1 7 | b |
1 7 | b | = | - | 30 7 |
| b | = | - | 30 7 | ÷ | 1 7 |
| = | - | 30 7 | × | 7 |
| = | - | 30 | × | 1 |
| b | = | - | 30 |