双变量加减12%

Question

所以我使用的是双变量。我只是需要帮助找出如何将它们相加，然后从答案中提取12%。

public class Hello {
//c
    public static void main(String[ ] args) {
        first_number = 10.5;
        second_number = 20.8;
        answer = first_number + second_number;

        System.out.println("Additional Total="+ answer-12%);
    }
}

Answer 1

得到总数的88%

System.out.println("Additional Total = " + answer * .88);

Answer 2

将和乘以(1 - 0.12)