import java.util.*;    public class Equation2 {        public static void main(String[] args) {            Scanner in = new Scanner(System.in);            double a,b,c;            double x1,x2;            System.out.print("请输入a：");    a = in.nextInt();            System.out.print("请输入b：");    b = in.nextInt();            System.out.print("请输入c：");    c = in.nextInt();            x1 = ((-b)+Math.sqrt(b*b-4*a*c))/(2*a);            x2 = ((-b)-Math.sqrt(b*b-4*a*c))/(2*a);            System.out.print("x1="+x1+"\tx2="+x2);        }    }