| 90 | ÷ | ( | 1 | + | x | ) | + | 90 | ÷ | ( | 1 | + | x | ) | × | ( | 1 | + | x | ) | + | 90 | ÷ | ( | 1 | + | x | ) | × | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | ÷ | ( | 1 | + | x | ) | × | ( | 1 | + | x | ) | = | 0 |
| Multiply both sides of the equation by: | ( | 1 | + | x | ) |
| 90 | + | 90 | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | = | 0 |
| 90 | + | 90 | × | 1 | + | 90 | x | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | ( | 1 | + | x | ) | = | 0 |
| 90 | + | 90 | + | 90 | x | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | = | 0 |
| 180 | + | 90 | x | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | = | 0 |
| 180 | + | 90 | x | + | 90 | × | 1 | ( | 1 | + | x | ) | + | 90 | x | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | = | 0 |
| 180 | + | 90 | x | + | 90 | ( | 1 | + | x | ) | + | 90 | x | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | ( | 1 | + | x | ) | = | 0 |
| 180 | + | 90 | x | + | 90 | × | 1 | + | 90 | x | + | 90 | x | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | = | 0 |
| 180 | + | 90 | x | + | 90 | + | 90 | x | + | 90 | x | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | = | 0 |
| 270 | + | 180 | x | + | 90 | x | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | = | 0 |
| 270 | + | 180 | x | + | 90 | x | × | 1 | + | 90 | x | x | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | = | 0 |
| 270 | + | 180 | x | + | 90 | x | + | 90 | x | x | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | ( | 1 | + | x | ) | = | 0 |
| 270 | + | 270 | x | + | 90 | x | x | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | ( | 1 | + | x | ) | = | 0 |
| 270 | + | 270 | x | + | 90 | x | x | + | 90 | × | 1 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | x | = | 0 |
| 270 | + | 270 | x | + | 90 | x | x | + | 90 | ( | 1 | + | x | ) | ( | 1 | + | x | ) | + | 90 | x | ( | 1 | + | x | ) | = | 0 |
| 270 | + | 270 | x | + | 90 | x | x | + | 90 | × | 1 | ( | 1 | + | x | ) | + | 90 | x | ( | 1 | + | x | ) | = | 0 |
| 270 | + | 270 | x | + | 90 | x | x | + | 90 | ( | 1 | + | x | ) | + | 90 | x | ( | 1 | + | x | ) | + | 90 | = | 0 |
| 270 | + | 270 | x | + | 90 | x | x | + | 90 | × | 1 | + | 90 | x | + | 90 | x | = | 0 |
| 270 | + | 270 | x | + | 90 | x | x | + | 90 | + | 90 | x | + | 90 | x | ( | 1 | + | x | ) | = | 0 |
| 360 | + | 360 | x | + | 90 | x | x | + | 90 | x | ( | 1 | + | x | ) | + | 90 | x | ( | 1 | + | x | ) | = | 0 |
| 360 | + | 360 | x | + | 90 | x | x | + | 90 | x | × | 1 | + | 90 | x | x | = | 0 |
| 360 | + | 360 | x | + | 90 | x | x | + | 90 | x | + | 90 | x | x | + | 90 | = | 0 |
| 360 | + | 450 | x | + | 90 | x | x | + | 90 | x | x | + | 90 | x | ( | 1 | + | x | ) | = | 0 |
| 360 | + | 450 | x | + | 90 | x | x | + | 90 | x | x | + | 90 | x | × | 1 | = | 0 |
| 360 | + | 450 | x | + | 90 | x | x | + | 90 | x | x | + | 90 | x | ( | 1 | + | x | ) | = | 0 |