| 7 | x | × | 6 | − | 90 | x | × | 5 | + | 465 | x | × | 4 | − | 1236 | x | × | 3 | = | 0 |
| Left side of the equation = | 42 | x | − | 450 | x | + | 1860 | x | − | 3708 | x | + | 3564 | x | − | 1320 | x |
| = | - | 12 | x | + | 392 |
| - | 12 | x | + | 392 | = | 0 |
| - | 12 | x | = | 0 | − | 392 |
| - | 12 | x | = | - | 392 |
| 392 | = | 12 | x |
| 12 | x | = | 392 |
| x | = | 392 | ÷ | 12 |
| = | 392 | × | 1 12 |
| = | 98 | × | 1 3 |
| x | = | 98 3 |
| x | = | 32.666667 |