| 300 | ( | 60 | × | 8 | − | 40 | × | 23 2 | ) | + | 60 | x | − | 40 | × | 80 | = | 6400 |
| Left side of the equation = | 300 | ( | 60 | × | 8 | − | 40 | × | 23 2 | ) | + | 60 | x | − | 3200 |
| 300 | ( | 60 | × | 8 | − | 40 | × | 23 2 | ) | + | 60 | x | − | 3200 | = | 6400 |
| Left side of the equation = | 300 | × | 60 | × | 8 | − | 300 | × | 40 | × | 23 2 | + | 60 | x | − | 3200 |
| = | 144000 | − | 138000 | + | 60 | x | − | 3200 |
| = | 2800 | + | 60 | x |
| 2800 | + | 60 | x | = | 6400 |
| 60 | x | = | 6400 | − | 2800 |
| 60 | x | = | 3600 |
| x | = | 3600 | ÷ | 60 |
| = | 3600 | × | 1 60 |
| = | 60 | × | 1 |
| x | = | 60 |