21 2 | = | 11 10 | ( | 1 | + | X | ) | ÷ | 72 5 | + | X |
| Right side of the equation = | 11 144 | ( | 1 | + | X | ) | + | X |
21 2 | = | 11 144 | ( | 1 | + | X | ) | + | X |
| Right side of the equation = | 11 144 | × | 1 | + | 11 144 | X | + | X |
| = | 11 144 | + | 11 144 | X | + | X |
| = | 11 144 | + | 155 144 | X |
21 2 | = | 11 144 | + | 155 144 | X |
| - | 155 144 | X | = | 11 144 | − | 21 2 |
| - | 155 144 | X | = | - | 1501 144 |
1501 144 | = | 155 144 | X |
155 144 | X | = | 1501 144 |
| X | = | 1501 144 | ÷ | 155 144 |
| = | 1501 144 | × | 144 155 |
| = | 1501 | × | 1 155 |
| X | = | 1501 155 |
| X | = | 9.683871 |