| 3 | ( | 35 | + | x | ) | = | 4 | ( | 35 | − | x | ) |
| Left side of the equation = | 3 | × | 35 | + | 3 | x |
| = | 105 | + | 3 | x |
| 105 | + | 3 | x | = | 4 | ( | 35 | − | x | ) |
| Right side of the equation = | 4 | × | 35 | − | 4 | x |
| = | 140 | − | 4 | x |
| 105 | + | 3 | x | = | 140 | − | 4 | x |
| 3 | x | + | 4 | x | = | 140 | − | 105 |
| 7 | x | = | 140 | − | 105 |
| 7 | x | = | 35 |
| x | = | 35 | ÷ | 7 |
| = | 35 | × | 1 7 |
| = | 5 | × | 1 |
| x | = | 5 |