| ( | 7 100 | − | x | ) | ÷ | ( | 7 100 | − | 5 100 | ) | = | ( | 150 | − | 120 | ) | ÷ | ( | 150 | − | 100 | ) |
| Multiply both sides of the equation by: | ( | 7 100 | − | 5 100 | ) | , | ( | 150 | − | 100 | ) |
| ( | 7 100 | − | x | ) | ( | 150 | − | 100 | ) | = | ( | 150 | − | 120 | ) | ( | 7 100 | − | 5 100 | ) |
7 100 | ( | 150 | − | 100 | ) | − | x | ( | 150 | − | 100 | ) | = | ( | 150 | − | 120 | ) | ( | 7 100 | − | 5 100 | ) |
7 100 | ( | 150 | − | 100 | ) | − | x | ( | 150 | − | 100 | ) | = | 150 | ( | 7 100 | − | 5 100 | ) | − | 120 | ( | 7 100 | − | 5 100 | ) |
7 100 | × | 150 | − | 7 100 | × | 100 | − | x | ( | 150 | − | 100 | ) | = | 150 | ( | 7 100 | − | 5 100 | ) | − | 120 | ( | 7 100 | − | 5 100 | ) |
7 100 | × | 150 | − | 7 100 | × | 100 | − | x | ( | 150 | − | 100 | ) | = | 150 | × | 7 100 | − | 150 | × | 5 100 | − | 120 | ( | 7 100 | − | 5 100 | ) |
21 2 | − | 7 | − | x | ( | 150 | − | 100 | ) | = | 21 2 | − | 15 2 | − | 120 | ( | 7 100 | − | 5 100 | ) |
7 2 | − | x | ( | 150 | − | 100 | ) | = | 3 | − | 120 | ( | 7 100 | − | 5 100 | ) |
7 2 | − | x | × | 150 | + | x | × | 100 | = | 3 | − | 120 | ( | 7 100 | − | 5 100 | ) |
7 2 | − | x | × | 150 | + | x | × | 100 | = | 3 | − | 120 | × | 7 100 | + | 120 | × | 5 100 |
7 2 | − | x | × | 150 | + | x | × | 100 | = | 3 | − | 42 5 | + | 6 |
7 2 | − | 50 | x | = | 3 5 |
| - | 50 | x | = | 3 5 | − | 7 2 |
| - | 50 | x | = | - | 29 10 |
29 10 | = | 50 | x |
| 50 | x | = | 29 10 |
| x | = | 29 10 | ÷ | 50 |
| = | 29 10 | × | 1 50 |
| x | = | 29 500 |
| x | = | 0.058 |