| ( | X | − | 400 | − | 402 | − | 8625 | − | 3500 | ) | ÷ | 57780 | = | 17 20 |
| Left side of the equation = | X | × | 1 57780 | − | 400 | × | 1 57780 | − | 402 | × | 1 57780 | − | 8625 | × | 1 57780 | − | 3500 | × | 1 57780 |
| = | X | × | 1 57780 | − | 20 2889 | − | 67 9630 | − | 575 3852 | − | 175 2889 |
| = | 1 57780 | X | − | 4309 19260 |
1 57780 | X | − | 4309 19260 | = | 17 20 |
1 57780 | X | = | 17 20 | + | 4309 19260 |
1 57780 | X | = | 1034 963 |
| X | = | 1034 963 | ÷ | 1 57780 |
| = | 1034 963 | × | 57780 |
| = | 1034 107 | × | 6420 |
| X | = | 6638280 107 |
| X | = | 62040 |