| ( | 19 20 | + | x | ) | × | 21 20 | = | 1 | + | x |
| Left side of the equation = | 19 20 | × | 21 20 | + | x | × | 21 20 |
| = | 399 400 | + | x | × | 21 20 |
399 400 | + | 21 20 | x | = | 1 | + | x |
21 20 | x | − | x | = | 1 | − | 399 400 |
1 20 | x | = | 1 | − | 399 400 |
1 20 | x | = | 1 400 |
| x | = | 1 400 | ÷ | 1 20 |
| = | 1 400 | × | 20 |
| = | 1 20 | × | 1 |
| x | = | 1 20 |
| x | = | 0.05 |