80 | X | + | 80 | X | ( | 1 | − | 5 100 | ) | + | 80 | X | ( | 1 | − | 15 100 | ) | = | 2400 |
方程左边 = | 80 | X | + | 80 | X | × | 1 | − | 80 | X | × | 5 100 | + | 80 | X | ( | 1 | − | 15 100 | ) |
= | 80 | X | + | 80 | X | − | 4 | X | + | 80 | X | ( | 1 | − | 15 100 | ) |
= | 156 | X | + | 80 | X | ( | 1 | − | 15 100 | ) |
= | 156 | X | + | 80 | X | × | 1 | − | 80 | X | × | 15 100 |
= | 156 | X | + | 80 | X | − | 12 | X |
= | 224 | X |
224 | X | = | 2400 |
X | = | 2400 | ÷ | 224 |
= | 2400 | × | 1 224 |
= | 75 | × | 1 7 |
X | = | 75 7 |
X | = | 10.714286 |