| ( | N | − | 7 | ) | ÷ | ( | N | + | 1 | ) | = | 3 4 | − | 3 4 | ( | 161 500 | ) | × | 1417 2500 |
| 方程两边同时乘以: | ( | N | + | 1 | ) |
| ( | N | − | 7 | ) | = | 3 4 | ( | N | + | 1 | ) | − | 3 4 | ( | 161 500 | ) | × | 1417 2500 | ( | N | + | 1 | ) |
| N | − | 7 | = | 3 4 | ( | N | + | 1 | ) | − | 3 4 | ( | 161 500 | ) | × | 1417 2500 | ( | N | + | 1 | ) |
| N | − | 7 | = | 3 4 | N | + | 3 4 | × | 1 | − | 3 4 | ( | 161 500 | ) | × | 1417 2500 | ( | N | + | 1 | ) |
| N | − | 7 | = | 3 4 | N | + | 3 4 | − | 4251 10000 | ( | 161 500 | ) | ( | N | + | 1 | ) |
| N | − | 7 | = | 3 4 | N | + | 3 4 | − | 4251 10000 | × | 161 500 | ( | N | + | 1 | ) |
| N | − | 7 | = | 3 4 | N | + | 3 4 | − | 684411 5000000 | ( | N | + | 1 | ) |
| N | − | 7 | = | 3 4 | N | + | 3 4 | − | 684411 5000000 | N | − | 684411 5000000 | × | 1 |
| N | − | 7 | = | 3 4 | N | + | 3 4 | − | 684411 5000000 | N | − | 684411 5000000 |
| N | − | 7 | = | 3065589 5000000 | N | + | 3065589 5000000 |
| N | − | 3065589 5000000 | N | = | 3065589 5000000 | + | 7 |
1934411 5000000 | N | = | 3065589 5000000 | + | 7 |
1934411 5000000 | N | = | 38065589 5000000 |
| N | = | 38065589 5000000 | ÷ | 1934411 5000000 |
| = | 38065589 5000000 | × | 5000000 1934411 |
| = | 38065589 | × | 1 1934411 |
| N | = | 38065589 1934411 |
| N | = | 19.678129 |