| 3 | x | − | 2 | x | − | 13 | = | 5 |
| Left side of the equation = | 1 | x | − | 13 |
| 1 | x | − | 13 | = | 5 |
| 1 | x | = | 5 | + | 13 |
| x | = | 5 | + | 13 |
| x | = | 18 |
| 4 | x | − | 3 | ( | 20 | − | x | ) | + | 4 | = | 0 |
| Left side of the equation = | 4 | x | − | 3 | × | 20 | + | 3 | x | + | 4 |
| = | 4 | x | − | 60 | + | 3 | x | + | 4 |
| = | 7 | x | − | 56 |
| 7 | x | − | 56 | = | 0 |
| 7 | x | = | 0 | + | 56 |
| 7 | x | = | 56 |
| x | = | 56 | ÷ | 7 |
| = | 56 | × | 1 7 |
| = | 8 | × | 1 |
| x | = | 8 |
| 2 | ( | x | − | 3 | ) | = | 29 5 |
| Left side of the equation = | 2 | x | − | 2 | × | 3 |
| = | 2 | x | − | 6 |
| 2 | x | − | 6 | = | 29 5 |
| 2 | x | = | 29 5 | + | 6 |
| 2 | x | = | 59 5 |
| x | = | 59 5 | ÷ | 2 |
| = | 59 5 | × | 1 2 |
| x | = | 59 10 |
| x | = | 5.9 |
| 5 | x | × | 4 | + | 4 | x | × | 2 | − | 35 | = | 77 |
| Left side of the equation = | 20 | x | + | 8 | x | − | 35 |
| = | 28 | x | − | 35 |
| 28 | x | − | 35 | = | 77 |
| 28 | x | = | 77 | + | 35 |
| 28 | x | = | 112 |
| x | = | 112 | ÷ | 28 |
| = | 112 | × | 1 28 |
| = | 4 | × | 1 |
| x | = | 4 |
| 4 | x | × | 4 | + | 11 | = | 131 | + | 2 | x | × | 4 |
| Left side of the equation = | 16 | x | + | 11 |
| 16 | x | + | 11 | = | 131 | + | 2 | x | × | 4 |
| Right side of the equation = | 131 | + | 8 | x |
| 16 | x | + | 11 | = | 131 | + | 8 | x |
| 16 | x | − | 8 | x | = | 131 | − | 11 |
| 8 | x | = | 131 | − | 11 |
| 8 | x | = | 120 |
| x | = | 120 | ÷ | 8 |
| = | 120 | × | 1 8 |
| = | 15 | × | 1 |
| x | = | 15 |
| 5 | x | + | 34 | = | 50 | − | 3 | x |
| 5 | x | + | 3 | x | = | 50 | − | 34 |
| 8 | x | = | 50 | − | 34 |
| 8 | x | = | 16 |
| x | = | 16 | ÷ | 8 |
| = | 16 | × | 1 8 |
| = | 2 | × | 1 |
| x | = | 2 |