| ( | 180 | + | 10 | x | ) | ( | 180 | − | x | ) | + | ( | 140 | − | x | ) | ( | 240 | + | 10 | x | ) | = | 184400 |
| Left side of the equation = | 180 | ( | 180 | − | x | ) | + | 10 | x | ( | 180 | − | x | ) | + | ( | 140 | − | x | ) | ( | 240 | + | 10 | x | ) |
| = | 180 | × | 180 | − | 180 | x | + | 10 | x | ( | 180 | − | x | ) | + | ( | 140 | − | x | ) | ( | 240 | + | 10 | x | ) |
| = | 32400 | − | 180 | x | + | 10 | x | ( | 180 | − | x | ) | + | ( | 140 | − | x | ) | ( | 240 | + | 10 | x | ) |
| = | 32400 | − | 180 | x | + | 10 | x | × | 180 | − | 10 | x | x | + | ( | 140 | − | x | ) | ( | 240 | + | 10 | x | ) |
| = | 32400 | − | 180 | x | + | 1800 | x | − | 10 | x | x | + | ( | 140 | − | x | ) | ( | 240 | + | 10 | x | ) |
| = | 32400 | + | 1620 | x | − | 10 | x | x | + | ( | 140 | − | x | ) | ( | 240 | + | 10 | x | ) |
| = | 32400 | + | 1620 | x | − | 10 | x | x | + | 140 | ( | 240 | + | 10 | x | ) | − | x | ( | 240 | + | 10 | x | ) |
| = | 32400 | + | 1620 | x | − | 10 | x | x | + | 140 | × | 240 | + | 140 | × | 10 | x | − | x |
| = | 32400 | + | 1620 | x | − | 10 | x | x | + | 33600 | + | 1400 | x | − | x | ( | 240 | + | 10 | x | ) |
| = | 66000 | + | 3020 | x | − | 10 | x | x | − | x | ( | 240 | + | 10 | x | ) |
| = | 66000 | + | 3020 | x | − | 10 | x | x | − | x | × | 240 | − | x | × | 10 | x |
| = | 66000 | + | 2780 | x | − | 10 | x | x | − | x | × | 10 | x |
| 66000 | + | 2780 | x | − | 10 | x | x | − | x | × | 10 | x | = | 184400 |