( | x | − | 2019 | ) | ( | x | − | 2020 | ) | = | 2021 | × | 2022 |
方程左边 = | x | ( | x | − | 2020 | ) | − | 2019 | ( | x | − | 2020 | ) |
= | x | x | − | x | × | 2020 | − | 2019 | ( | x | − | 2020 | ) |
= | x | x | − | 2020 | x | − | 2019 | x | + | 2019 | × | 2020 |
= | x | x | − | 2020 | x | − | 2019 | x | + | 4078380 |
= | x | x | − | 4039 | x | + | 4078380 |
x | x | − | 4039 | x | + | 4078380 | = | 2021 | × | 2022 |
方程右边 = | 4086462 |
x | x | − | 4039 | x | + | 4078380 | = | 4086462 |