| 90 | = | 411 | + | ( | 100 | x | ) | ÷ | ( | 6 | + | x | ) |
| 方程两边同时乘以: | ( | 6 | + | x | ) |
| 90 | ( | 6 | + | x | ) | = | 411 | ( | 6 | + | x | ) | + | ( | 100 | x | ) |
| 90 | × | 6 | + | 90 | x | = | 411 | ( | 6 | + | x | ) | + | ( | 100 | x | ) |
| 90 | × | 6 | + | 90 | x | = | 411 | × | 6 | + | 411 | x | + | ( | 100 | x | ) |
| 540 | + | 90 | x | = | 2466 | + | 411 | x | + | ( | 100 | x | ) |
| 540 | + | 90 | x | = | 2466 | + | 411 | x | + | 100 | x |
| 540 | + | 90 | x | = | 2466 | + | 511 | x |
| 90 | x | − | 511 | x | = | 2466 | − | 540 |
| - | 421 | x | = | 2466 | − | 540 |
| - | 421 | x | = | 1926 |
| - | 1926 | = | 421 | x |
| 421 | x | = | - | 1926 |
| x | = | - | 1926 | ÷ | 421 |
| = | - | 1926 | × | 1 421 |
| x | = | - | 1926 421 |
| x | = | - 4.574822 |