输出结果为什么不对呢？谢谢老师！！

public class HelloWorld{

    public static void main(String[] args) {

   int one = 10 ;

        int two = 20 ;

        int three = 0;

        three = one + two;

        System.out.println("three = one + two ==>" + three);

        three =+ one;

        System.out.println("three =+ one ==>" + three);

        three -= one;

        System.out.println("three -= one ==>" + three);

        three *= one;

        System.out.println("three *= one ==>" + three);

        three /= one;

        System.out.println("three /= one ==>" + three);

        three %= one;

        System.out.println("three %= one ==>" + three);

}

}

输出结果为什么是这个呢？

three = one + two ==>30

three =+ one ==>10

three -= one ==>0

three *= one ==>0

three /= one ==>0

three %= one ==>0