| 98 | ÷ | 80 | = | x | ÷ | 20 | × | 20 100 |
| Left side of the equation = | 49 40 |
49 40 | = | x | ÷ | 20 | × | 20 100 |
| Right side of the equation = | x | × | 1 100 |
49 40 | = | 1 100 | x |
| - | 1 100 | x | = | - | 49 40 |
49 40 | = | 1 100 | x |
1 100 | x | = | 49 40 |
| x | = | 49 40 | ÷ | 1 100 |
| = | 49 40 | × | 100 |
| = | 49 2 | × | 5 |
| x | = | 245 2 |
| x | = | 122.5 |