主要方法有加减消元法和代入消元法2种.代入消元法：由（1）得：x/4=7-y/3x=28-4y/3 (3)把（3）代入方程（2）,得：2/3(28-4y/3)+1/2y=1456/3-8y/9+1/2y=14 ...