| ( | x | + | 15 | ) | ( | 35 | + | 3 | x | ) | = | 1000 |
| Left side of the equation = | x | ( | 35 | + | 3 | x | ) | + | 15 | ( | 35 | + | 3 | x | ) |
| = | x | × | 35 | + | x | × | 3 | x | + | 15 | ( | 35 | + | 3 | x | ) |
| = | 35 | x | + | x | × | 3 | x | + | 15 | × | 35 | + | 15 | × | 3 | x |
| = | 35 | x | + | x | × | 3 | x | + | 525 | + | 45 | x |
| = | 80 | x | + | x | × | 3 | x | + | 525 |
| 80 | x | + | x | × | 3 | x | + | 525 | = | 1000 |
| x1= | - | 95 3 |
| x2=5 |