| ( | 1 | + | X | + | 3 20 | ) | ÷ | 1 | + | X | = | 3 50 | ÷ | 3 5 |
| Left side of the equation = | 1 | × | 1 | + | X | × | 1 | + | 3 20 | × | 1 | + | X |
| = | 1 | + | X | × | 1 | + | 3 20 | + | X |
| = | 23 20 | + | 2 | X |
23 20 | + | 2 | X | = | 3 50 | ÷ | 3 5 |
| Right side of the equation = | 1 10 |
23 20 | + | 2 | X | = | 1 10 |
| 2 | X | = | 1 10 | − | 23 20 |
| 2 | X | = | - | 21 20 |
| X | = | - | 21 20 | ÷ | 2 |
| = | - | 21 20 | × | 1 2 |
| X | = | - | 21 40 |
| X | = | - 0.525 |