| 4200 | × | 3 20 | ( | x | + | 7 10 | ) | + | 620 | ( | 3 10 | − | x | ) | + | 1600 | x | + | 24000 | × | 7 10 | = | 16000 | ( | 3 20 | x | + | 3 20 | × | 7 10 | + | 1 | ) |
| Left side of the equation = | 630 | ( | x | + | 7 10 | ) | + | 620 | ( | 3 10 | − | x | ) | + | 1600 | x | + | 16800 |
| 630 | ( | x | + | 7 10 | ) | + | 620 | ( | 3 10 | − | x | ) | + | 1600 | x | + | 16800 | = | 16000 | ( | 3 20 | x | + | 3 20 | × | 7 10 | + | 1 | ) |
| Left side of the equation = | 630 | x | + | 630 | × | 7 10 | + | 620 | ( | 3 10 | − | x | ) | + | 1600 | x | + | 16800 |
| = | 630 | x | + | 441 | + | 620 | ( | 3 10 | − | x | ) | + | 1600 | x | + | 16800 |
| = | 2230 | x | + | 17241 | + | 620 | ( | 3 10 | − | x | ) |
| = | 2230 | x | + | 17241 | + | 620 | × | 3 10 | − | 620 | x |
| = | 2230 | x | + | 17241 | + | 186 | − | 620 | x |
| = | 1610 | x | + | 17427 |
| 1610 | x | + | 17427 | = | 16000 | ( | 3 20 | x | + | 3 20 | × | 7 10 | + | 1 | ) |
| Right side of the equation = | 16000 | × | 3 20 | x | + | 16000 | × | 3 20 | × | 7 10 | + | 16000 | × | 1 |
| = | 2400 | x | + | 1680 | + | 16000 |
| = | 2400 | x | + | 17680 |
| 1610 | x | + | 17427 | = | 2400 | x | + | 17680 |
| 1610 | x | − | 2400 | x | = | 17680 | − | 17427 |
| - | 790 | x | = | 17680 | − | 17427 |
| - | 790 | x | = | 253 |
| - | 253 | = | 790 | x |
| 790 | x | = | - | 253 |
| x | = | - | 253 | ÷ | 790 |
| = | - | 253 | × | 1 790 |
| x | = | - | 253 790 |
| x | = | - 0.320253 |