Android：错误：解析XML时出错：格式不正确（令牌无效）

There's an error in my activity_main.xml on line 13 (Wich you can see below). It says "Error parsing XML: not well-formed(invalid token)". In addition to that my R.java has killed itself. I've found ways to fix it, but they won't work (At least I think it's because of that) until this error is fixed. There's an error in my activity_main.xml on lin