| - | 5 | − | 5 | ÷ | r | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 4 | ) | + | ( | 4 | ÷ | r | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | ÷ | ( | 1 | + | r | ) | × | 30 | + | 71 2 | ÷ | ( | 1 | + | r | ) | × | 50 | = | 0 |
| Multiply both sides of the equation by: | r |
| - | 5 | r | − | 5 | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 4 | ) | + | ( | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | ÷ | ( | 1 | + | r | ) | × | 30 | × | 1 | + | 71 2 | ÷ | ( | 1 | + | r | ) | × | 50 | r | = | 0 |
| - | 5 | r | − | 5 | × | 1 | + | 5 | × | 1 | ÷ | ( | 1 | + | r | ) | × | 4 | + | ( | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | ÷ | ( | 1 | + | r | ) | × | 30 | × | 1 | = | 0 |
| - | 5 | r | − | 5 | + | 20 | ÷ | ( | 1 | + | r | ) | + | ( | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | ÷ | ( | 1 | + | r | ) | × | 30 | + | 1775 | ÷ | ( | 1 | + | r | ) | × | r | = | 0 |
| Multiply both sides of the equation by: | ( | 1 | + | r | ) |
| - | 5 | r | ( | 1 | + | r | ) | − | 5 | ( | 1 | + | r | ) | + | 20 | + | ( | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | × | 30 | + | 1775 | r | = | 0 |
| - | 5 | r | × | 1 | − | 5 | r | r | − | 5 | ( | 1 | + | r | ) | + | 20 | + | ( | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | × | 30 | + | 1775 | = | 0 |
| - | 5 | r | − | 5 | r | r | − | 5 | ( | 1 | + | r | ) | + | 20 | + | ( | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | × | 30 | + | 1775 | r | = | 0 |
| 1770 | r | − | 5 | r | r | − | 5 | ( | 1 | + | r | ) | + | 20 | + | ( | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | × | 30 | = | 0 |
| 1770 | r | − | 5 | r | r | − | 5 | × | 1 | − | 5 | r | + | 20 | + | ( | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | × | 30 | = | 0 |
| 1770 | r | − | 5 | r | r | − | 5 | − | 5 | r | + | 20 | + | ( | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | × | 30 | = | 0 |
| 1765 | r | − | 5 | r | r | + | 15 | + | ( | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | ) | × | 30 | = | 0 |
| 1765 | r | − | 5 | r | r | + | 15 | + | 4 | ÷ | 1 | × | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | × | 30 | = | 0 |
| 1765 | r | − | 5 | r | r | + | 15 | + | 120 | ( | 1 | − | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | ) | = | 0 |
| 1765 | r | − | 5 | r | r | + | 15 | + | 120 | × | 1 | − | 120 | × | 1 | ÷ | ( | 1 | + | r | ) | × | 21 | = | 0 |
| 1765 | r | − | 5 | r | r | + | 15 | + | 120 | − | 2520 | ÷ | ( | 1 | + | r | ) | = | 0 |
| 1765 | r | − | 5 | r | r | + | 135 | − | 2520 | ÷ | ( | 1 | + | r | ) | = | 0 |
| Multiply both sides of the equation by: | ( | 1 | + | r | ) |
| 1765 | r | ( | 1 | + | r | ) | − | 5 | r | r | ( | 1 | + | r | ) | + | 135 | ( | 1 | + | r | ) | − | 2520 | = | 0 |
| 1765 | r | × | 1 | + | 1765 | r | r | − | 5 | r | r | ( | 1 | + | r | ) | + | 135 | ( | 1 | + | r | ) | = | 0 |
| 1765 | r | + | 1765 | r | r | − | 5 | r | r | ( | 1 | + | r | ) | + | 135 | ( | 1 | + | r | ) | − | 2520 | = | 0 |
| 1765 | r | + | 1765 | r | r | − | 5 | r | r | × | 1 | − | 5 | r | r | = | 0 |
| 1765 | r | + | 1765 | r | r | − | 5 | r | r | − | 5 | r | r | r | = | 0 |
| 1765 | r | + | 1765 | r | r | − | 5 | r | r | − | 5 | r | r | r | = | 0 |
| 1765 | r | + | 1765 | r | r | − | 5 | r | r | − | 5 | r | r | r | = | 0 |