| ( | 1 | + | 7 20 | × | 10 | x | ) | ( | 1 | + | x | ) | ÷ | 7 20 | = | 9 50 |
| Left side of the equation = | 1 | ( | 1 | + | x | ) | × | 20 7 | + | 7 20 | × | 10 | x | ( | 1 | + | x | ) | × | 20 7 |
| = | 20 7 | ( | 1 | + | x | ) | + | 10 | x | ( | 1 | + | x | ) |
| = | 20 7 | × | 1 | + | 20 7 | x | + | 10 | x | ( | 1 | + | x | ) |
| = | 20 7 | + | 20 7 | x | + | 10 | x | ( | 1 | + | x | ) |
| = | 20 7 | + | 20 7 | x | + | 10 | x | × | 1 | + | 10 | x | x |
| = | 20 7 | + | 20 7 | x | + | 10 | x | + | 10 | x | x |
| = | 20 7 | + | 90 7 | x | + | 10 | x | x |
20 7 | + | 90 7 | x | + | 10 | x | x | = | 9 50 |