| ( | ( | 2000 | − | x | ) | × | 7 20 | + | 450 | ) | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | = | x |
| Left side of the equation = | ( | 2000 | − | x | ) | × | 7 20 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 2000 | × | 7 20 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | − | x | × | 7 20 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 700 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | − | x | × | 7 20 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 700 | × | 1 | + | 700 | × | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | − | x | × | 7 20 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 700 | + | 1 10 | ( | 2000 | − | x | ) | − | x | × | 7 20 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 700 | + | 1 10 | × | 2000 | − | 1 10 | x | − | x | × | 7 20 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 700 | + | 200 | − | 1 10 | x | − | x | × | 7 20 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 900 | − | 1 10 | x | − | x | × | 7 20 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 900 | − | 1 10 | x | − | x | × | 7 20 | × | 1 | − | x | × | 7 20 | × | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | + | 450 |
| = | 900 | − | 1 10 | x | − | x | × | 7 20 | − | x | × | 1 20000 | ( | 2000 | − | x | ) | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 900 | − | 9 20 | x | − | x | × | 1 20000 | ( | 2000 | − | x | ) | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 900 | − | 9 20 | x | − | x | × | 1 20000 | × | 2000 | + | x | × | 1 20000 | x | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 900 | − | 9 20 | x | − | x | × | 1 10 | + | x | × | 1 20000 | x | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 900 | − | 11 20 | x | + | x | × | 1 20000 | x | + | 450 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 14000 | ) |
| = | 900 | − | 11 20 | x | + | x | × | 1 20000 | x | + | 450 | × | 1 | + | 450 | × | 2 | ( | 2000 | − | x | ) | ÷ | 14000 |
| = | 900 | − | 11 20 | x | + | x | × | 1 20000 | x | + | 450 | + | 9 140 | ( | 2000 | − | x | ) |
| = | 1350 | − | 11 20 | x | + | x | × | 1 20000 | x | + | 9 140 | ( | 2000 | − | x | ) |
| = | 1350 | − | 11 20 | x | + | x | × | 1 20000 | x | + | 9 140 | × | 2000 | − | 9 140 | x |
| = | 1350 | − | 11 20 | x | + | x | × | 1 20000 | x | + | 900 7 | − | 9 140 | x |
| = | 10350 7 | − | 43 70 | x | + | x | × | 1 20000 | x |
10350 7 | − | 43 70 | x | + | x | × | 1 20000 | x | = | x |