| - | 80 | ÷ | 3 | × | ( | 2 | × | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 3 | ) | + | 80 | ÷ | 3 | × | ( | 40 | x | + | 40 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 4 | ) | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 90 | ÷ | 3 | = | 0 |
| Left side of the equation = | - | 80 3 | ( | 2 | × | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 3 | ) | + | 80 3 | ( | 40 | x | + | 40 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 4 | ) | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |
| - | 80 3 | ( | 2 | × | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 3 | ) | + | 80 3 | ( | 40 | x | + | 40 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 4 | ) | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) | = | 0 |
| Left side of the equation = | - | 80 3 | × | 2 | × | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | − | 80 3 | × | 3 | + | 80 3 | ( | 40 | x | + | 40 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 4 | ) | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 |
| = | - | 12800 9 | ( | 1 | − | x | ) | − | 80 | + | 80 3 | ( | 40 | x | + | 40 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 4 | ) | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 |
| = | - | 12800 9 | × | 1 | + | 12800 9 | x | − | 80 | + | 80 3 | ( | 40 | x | + | 40 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 4 | ) | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 |
| = | - | 12800 9 | + | 12800 9 | x | − | 80 | + | 80 3 | ( | 40 | x | + | 40 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 4 | ) | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 13520 9 | + | 12800 9 | x | + | 80 3 | ( | 40 | x | + | 40 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 4 | ) | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 |
| = | - | 13520 9 | + | 12800 9 | x | + | 80 3 | × | 40 | x | + | 80 3 | × | 40 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 80 3 | × | 4 |
| = | - | 13520 9 | + | 12800 9 | x | + | 3200 3 | x | + | 3200 9 | ( | 1 | − | x | ) | + | 320 3 | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 12560 9 | + | 22400 9 | x | + | 3200 9 | ( | 1 | − | x | ) | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 |
| = | - | 12560 9 | + | 22400 9 | x | + | 3200 9 | × | 1 | − | 3200 9 | x | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 |
| = | - | 12560 9 | + | 22400 9 | x | + | 3200 9 | − | 3200 9 | x | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 1040 | + | 6400 3 | x | + | 20 | ( | 30 | x | + | 10 | ( | 1 | − | x | ) | + | 2 | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 1040 | + | 6400 3 | x | + | 20 | × | 30 | x | + | 20 | × | 10 | ( | 1 | − | x | ) | + | 20 | × | 2 | − | 20 |
| = | - | 1040 | + | 6400 3 | x | + | 600 | x | + | 200 | ( | 1 | − | x | ) | + | 40 | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 1000 | + | 8200 3 | x | + | 200 | ( | 1 | − | x | ) | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 1000 | + | 8200 3 | x | + | 200 | × | 1 | − | 200 | x | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 |
| = | - | 1000 | + | 8200 3 | x | + | 200 | − | 200 | x | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 800 | + | 7600 3 | x | − | 20 | ( | 60 | ( | 1 | − | x | ) | + | 1 | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 800 | + | 7600 3 | x | − | 20 | × | 60 | ( | 1 | − | x | ) | − | 20 | × | 1 | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 800 | + | 7600 3 | x | − | 1200 | ( | 1 | − | x | ) | − | 20 | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 820 | + | 7600 3 | x | − | 1200 | ( | 1 | − | x | ) | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 820 | + | 7600 3 | x | − | 1200 | × | 1 | + | 1200 | x | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 820 | + | 7600 3 | x | − | 1200 | + | 1200 | x | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |
| = | - | 2020 | + | 11200 3 | x | + | 30 | ( | 80 | x | + | 80 | ÷ | 3 | × | ( | 1 | − | x | ) | + | 1 | ) | + | 20 | ( | 60 | x | + | 20 | ( | 1 | − | x | ) | + | 1 | ) |