( | 3 | x | − | 300 | ) | ( | 1 | + | 30 100 | ) | = | 0 |
方程左边 = | 3 | x | ( | 1 | + | 30 100 | ) | − | 300 | ( | 1 | + | 30 100 | ) |
= | 3 | x | × | 1 | + | 3 | x | × | 30 100 | − | 300 | ( | 1 | + | 30 100 | ) |
= | 3 | x | + | 9 10 | x | − | 300 | ( | 1 | + | 30 100 | ) |
= | 39 10 | x | − | 300 | ( | 1 | + | 30 100 | ) |
= | 39 10 | x | − | 300 | × | 1 | − | 300 | × | 30 100 |
= | 39 10 | x | − | 300 | − | 90 |
= | 39 10 | x | − | 390 |
39 10 | x | − | 390 | = | 0 |
39 10 | x | = | 0 | + | 390 |
39 10 | x | = | 390 |
x | = | 390 | ÷ | 39 10 |
= | 390 | × | 10 39 |
= | 10 | × | 10 |
x | = | 100 |