| x | × | 1500 | − | ( | 600 | x | + | 400 | ) | − | ( | 1500 | x | × | 13 100 | − | 80 | x | ) | × | 9 100 | = | 0 |
| Left side of the equation = | 1500 | x | − | 600 | x | − | 400 | − | ( | 1500 | x | × | 13 100 | − | 80 | x | ) | × | 9 100 |
| = | 900 | x | − | 400 | − | ( | 1500 | x | × | 13 100 | − | 80 | x | ) | × | 9 100 |
| = | 900 | x | − | 400 | − | 1500 | x | × | 13 100 | × | 9 100 | + | 80 | x | × | 9 100 |
| = | 900 | x | − | 400 | − | 351 20 | x | + | 36 5 | x |
| = | 17793 20 | x | − | 400 |
17793 20 | x | − | 400 | = | 0 |
17793 20 | x | = | 0 | + | 400 |
17793 20 | x | = | 400 |
| x | = | 400 | ÷ | 17793 20 |
| = | 400 | × | 20 17793 |
| x | = | 8000 17793 |
| x | = | 0.449615 |