我不明白啊

HelloWorld.java:8: error: ';' expected
        int three+=one;
                 ^
HelloWorld.java:8: error: not a statement
        int three+=one;
                   ^
HelloWorld.java:10: error: ';' expected
        int three-=one;
                 ^
HelloWorld.java:10: error: not a statement
        int three-=one;
                   ^
HelloWorld.java:12: error: ';' expected
        int three*=one;
                 ^
HelloWorld.java:12: error: not a statement
        int three*=one;
                   ^
HelloWorld.java:14: error: ';' expected
        int three/=one;
                 ^
HelloWorld.java:14: error: not a statement
        int three/=one;
                   ^
HelloWorld.java:16: error: ';' expected
        int three%=one;
                 ^
HelloWorld.java:16: error: not a statement
        int three%=one;
                   ^
10 errors