4 5 | ( | 100 | − | x | ) | + | ( | 1 | + | 100 100 | ) | x | = | 100 | ( | 1 | + | 4 100 | ) |
| Left side of the equation = | 4 5 | × | 100 | − | 4 5 | x | + | ( | 1 | + | 100 100 | ) | x |
| = | 80 | − | 4 5 | x | + | ( | 1 | + | 100 100 | ) | x |
| = | 80 | − | 4 5 | x | + | 1 | x | + | 100 100 | x |
| = | 80 | + | 6 5 | x |
| 80 | + | 6 5 | x | = | 100 | ( | 1 | + | 4 100 | ) |
| Right side of the equation = | 100 | × | 1 | + | 100 | × | 4 100 |
| = | 100 | + | 4 |
| = | 104 |
| 80 | + | 6 5 | x | = | 104 |
6 5 | x | = | 104 | − | 80 |
6 5 | x | = | 24 |
| x | = | 24 | ÷ | 6 5 |
| = | 24 | × | 5 6 |
| = | 4 | × | 5 |
| x | = | 20 |