【多选题】
矩阵的三种初等变换是
①
<img src=https://huaweicloudobs.ahjxjy.cn/8D1FA5FF7FD27CB9E4694A779ED15C79.png title=1.png alt=1.png/>
②
<img src=https://huaweicloudobs.ahjxjy.cn/529B3C0D275D02E67605C3E111A0973B.png title=2.png alt=2.png/>
③
<img src=https://huaweicloudobs.ahjxjy.cn/45B6F249416562FB2760DBA7DF288F2A.png title=4.png alt=4.png/>
④
<img src=https://huaweicloudobs.ahjxjy.cn/06CF7DBEB86A6E3F6C55567E0F354148.png title=3.png alt=3.png/>