( | 90 | + | 13 20 | x | ) | ÷ | ( | 150 | + | x | ) | = | 31 50 |
方程两边同时乘以: | ( | 150 | + | x | ) |
( | 90 | + | 13 20 | x | ) | = | 31 50 | ( | 150 | + | x | ) |
90 | + | 13 20 | x | = | 31 50 | ( | 150 | + | x | ) |
90 | + | 13 20 | x | = | 31 50 | × | 150 | + | 31 50 | x |
90 | + | 13 20 | x | = | 93 | + | 31 50 | x |
13 20 | x | − | 31 50 | x | = | 93 | − | 90 |
3 100 | x | = | 93 | − | 90 |
3 100 | x | = | 3 |
x | = | 3 | ÷ | 3 100 |
= | 3 | × | 100 3 |
= | 1 | × | 100 |
x | = | 100 |