| 3000 | ( | 1 | + | x | ) | ( | 1 | − | x | ) | = | 63 | × | 40 | + | 56 | × | 60 |
| Left side of the equation = | 3000 | × | 1 | ( | 1 | − | x | ) | + | 3000 | x | ( | 1 | − | x | ) |
| = | 3000 | ( | 1 | − | x | ) | + | 3000 | x | ( | 1 | − | x | ) |
| = | 3000 | × | 1 | − | 3000 | x | + | 3000 | x | ( | 1 | − | x | ) |
| = | 3000 | − | 3000 | x | + | 3000 | x | ( | 1 | − | x | ) |
| = | 3000 | − | 3000 | x | + | 3000 | x | × | 1 | − | 3000 | x | x |
| = | 3000 | − | 3000 | x | + | 3000 | x | − | 3000 | x | x |
| = | 3000 | − | 0 | x | − | 3000 | x | x |
| 3000 | − | 0 | x | − | 3000 | x | x | = | 63 | × | 40 | + | 56 | × | 60 |
| Right side of the equation = | 2520 | + | 3360 |
| = | 5880 |
| 3000 | − | 0 | x | − | 3000 | x | x | = | 5880 |