26706371 100000 | ( | 1 | + | 11 500 | ( | n | ( | n | − | 1 | ) | ÷ | 2 | ) | ) | = | 1800000 |
方程左边 = | 26706371 100000 | × | 1 | + | 26706371 100000 | × | 11 500 | ( | n | ( | n | − | 1 | ) | ÷ | 2 | ) |
= | 26706371 100000 | + | 293770081 50000000 | ( | n | ( | n | − | 1 | ) | ÷ | 2 | ) |
= | 26706371 100000 | + | 293770081 50000000 | n | ( | n | − | 1 | ) | ÷ | 2 |
= | 26706371 100000 | + | 293770081 100000000 | n | ( | n | − | 1 | ) |
= | 26706371 100000 | + | 293770081 100000000 | n | n | − | 293770081 100000000 | n | × | 1 |
= | 26706371 100000 | + | 293770081 100000000 | n | n | − | 293770081 100000000 | n |
26706371 100000 | + | 293770081 100000000 | n | n | − | 293770081 100000000 | n | = | 1800000 |