| ( | ( | 2000 | − | x | ) | ÷ | 4 | + | 300 | ) | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | = | x |
| Left side of the equation = | ( | 2000 | − | x | ) | ÷ | 4 | × | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 2000 | × | 1 4 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | − | x | × | 1 4 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 500 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | − | x | × | 1 4 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 500 | × | 1 | + | 500 | × | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | − | x | × | 1 4 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 500 | + | 5 7 | ( | 2000 | − | x | ) | − | x | × | 1 4 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 500 | + | 5 7 | × | 2000 | − | 5 7 | x | − | x | × | 1 4 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 500 | + | 10000 7 | − | 5 7 | x | − | x | × | 1 4 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 13500 7 | − | 5 7 | x | − | x | × | 1 4 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 13500 7 | − | 5 7 | x | − | x | × | 1 4 | × | 1 | − | x | × | 1 4 | × | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | + | 300 |
| = | 13500 7 | − | 5 7 | x | − | x | × | 1 4 | − | x | × | 1 2800 | ( | 2000 | − | x | ) | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 13500 7 | − | 27 28 | x | − | x | × | 1 2800 | ( | 2000 | − | x | ) | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 13500 7 | − | 27 28 | x | − | x | × | 1 2800 | × | 2000 | + | x | × | 1 2800 | x | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 13500 7 | − | 27 28 | x | − | x | × | 5 7 | + | x | × | 1 2800 | x | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 13500 7 | − | 47 28 | x | + | x | × | 1 2800 | x | + | 300 | ( | 1 | + | 2 | ( | 2000 | − | x | ) | ÷ | 1400 | ) |
| = | 13500 7 | − | 47 28 | x | + | x | × | 1 2800 | x | + | 300 | × | 1 | + | 300 | × | 2 | ( | 2000 | − | x | ) | ÷ | 1400 |
| = | 13500 7 | − | 47 28 | x | + | x | × | 1 2800 | x | + | 300 | + | 3 7 | ( | 2000 | − | x | ) |
| = | 15600 7 | − | 47 28 | x | + | x | × | 1 2800 | x | + | 3 7 | ( | 2000 | − | x | ) |
| = | 15600 7 | − | 47 28 | x | + | x | × | 1 2800 | x | + | 3 7 | × | 2000 | − | 3 7 | x |
| = | 15600 7 | − | 47 28 | x | + | x | × | 1 2800 | x | + | 6000 7 | − | 3 7 | x |
| = | 21600 7 | − | 59 28 | x | + | x | × | 1 2800 | x |
21600 7 | − | 59 28 | x | + | x | × | 1 2800 | x | = | x |