| ( | 60 | + | 2 | x | ) | ( | 35 | + | 2 | x | ) | = | 3150 |
| Left side of the equation = | 60 | ( | 35 | + | 2 | x | ) | + | 2 | x | ( | 35 | + | 2 | x | ) |
| = | 60 | × | 35 | + | 60 | × | 2 | x | + | 2 | x | ( | 35 | + | 2 | x | ) |
| = | 2100 | + | 120 | x | + | 2 | x | ( | 35 | + | 2 | x | ) |
| = | 2100 | + | 120 | x | + | 2 | x | × | 35 | + | 2 | x | × | 2 | x |
| = | 2100 | + | 120 | x | + | 70 | x | + | 4 | x | x |
| = | 2100 | + | 190 | x | + | 4 | x | x |
| 2100 | + | 190 | x | + | 4 | x | x | = | 3150 |
| x1= | - | 105 2 |
| x2=5 |