( | 30 | - | 7 | ) | ( | 80 | + | ( | 10 | x | × | 9 10 | ) | ) | = | 2400 |
方程左边 = | 30 | ( | 80 | + | ( | 10 | x | × | 9 10 | ) | ) | - | 7 | ( | 80 | + | ( | 10 | x | × | 9 10 | ) | ) |
= | 30 | × | 80 | + | 30 | ( | 10 | x | × | 9 10 | ) | - | 7 | ( | 80 | + | ( | 10 | x | × | 9 10 | ) | ) |
= | 2400 | + | 30 | ( | 10 | x | × | 9 10 | ) | - | 7 | ( | 80 | + | ( | 10 | x | × | 9 10 | ) | ) |
= | 2400 | + | 30 | × | 10 | x | × | 9 10 | - | 7 | ( | 80 | + | ( | 10 | x | × | 9 10 | ) | ) |
= | 2400 | + | 270 | x | - | 7 | ( | 80 | + | ( | 10 | x | × | 9 10 | ) | ) |
= | 2400 | + | 270 | x | - | 7 | × | 80 | - | 7 | ( | 10 | x | × | 9 10 | ) |
= | 2400 | + | 270 | x | - | 560 | - | 7 | ( | 10 | x | × | 9 10 | ) |
= | 1840 | + | 270 | x | - | 7 | ( | 10 | x | × | 9 10 | ) |
= | 1840 | + | 270 | x | - | 7 | × | 10 | x | × | 9 10 |
= | 1840 | + | 270 | x | - | 63 | x |
= | 1840 | + | 207 | x |
1840 | + | 207 | x | = | 2400 |
207 | x | = | 2400 | - | 1840 |
207 | x | = | 560 |
x | = | 560 | ÷ | 207 |
= | 560 | × | 1 207 |
x | = | 560 207 |
x | = | 2.705314 |