| X | ( | 1 | + | 50 100 | ) | − | X | × | 80 100 | − | X | × | 80 100 | × | 5 100 | = | 7 |
| Left side of the equation = | X | ( | 1 | + | 50 100 | ) | − | X | × | 80 100 | − | X | × | 1 25 |
| = | X | ( | 1 | + | 50 100 | ) | − | 21 25 | X |
| X | ( | 1 | + | 50 100 | ) | − | 21 25 | X | = | 7 |
| Left side of the equation = | X | × | 1 | + | X | × | 50 100 | − | 21 25 | X |
| = | 33 50 | X |
33 50 | X | = | 7 |
| X | = | 7 | ÷ | 33 50 |
| = | 7 | × | 50 33 |
| X | = | 350 33 |
| X | = | 10.606061 |