6 | x | + | 10 | ( | 300 | + | 500 | + | x | ) | = | 72 5 |
方程左边 = | 6 | x | + | 10 | × | 300 | + | 10 | × | 500 | + | 10 | x |
= | 6 | x | + | 3000 | + | 5000 | + | 10 | x |
= | 16 | x | + | 8000 |
16 | x | + | 8000 | = | 72 5 |
16 | x | = | 72 5 | - | 8000 |
16 | x | = | - | 39928 5 |
x | = | - | 39928 5 | ÷ | 16 |
= | - | 39928 5 | × | 1 16 |
= | - | 4991 5 | × | 1 2 |
x | = | - | 4991 10 |
x | = | - 499.1 |