C :

#include<stdio.h>
#include<math.h>
int main()
{
    int a,b,c,x;
	double y,s,s1;
	scanf("%d%d%d",&a,&b,&c);
	x=b*b-4*a*c;
	if(x<0)
		printf("%s\n","no answer");
    else if(x==0)
	{
        s=(-b)/(a*2.0);
		printf("%.4f\n",s);
	}
	else
	{
        y=sqrt(x);
		s=(-b+y)/(2.0*a);
		s1=(-b-y)/(2.0*a);
		printf("%.4f %.4f\n", s1, s);
	}
	return 0;
}

C++ :

#include <stdio.h>
#include <math.h>
int main() {
	int a, b, c, delta;
	double ans0, ans1, sqrt_delta;
	scanf("%d %d %d", &a, &b, &c);
	/* 计算delta的值（b*b-4*a*c）并分类讨论 */
	delta = b * b - 4 * a * c;
	if (delta > 0) {
		sqrt_delta = sqrt(delta);
		ans0 = (-b - sqrt_delta) / (2.0 * a);
		ans1 = (-b + sqrt_delta) / (2.0 * a);
		printf("%.4f %.4f\n", ans0, ans1);
	} else if (delta == 0) {
		ans0 = (-b) / (2.0 * a);
		printf("%.4f\n", ans0);
	} else {
		printf("no answer\n");
	}
	return 0;
}

Pascal :

var 
  a,b,c,d:double;

begin
  readln(a,b,c);
  d:=b*b-4*a*c;
  if(d<0) then writeln('no answer')
    else if(d<1e-8) then writeln(-b/(2*a):0:4)
      else writeln( (-b-sqrt(d))/(2*a):0:4 ,' ', (-b+sqrt(d))/(2*a):0:4 );
end.

Java :

import java.util.*;
public class Main {
	public static void main(String args[]) {
		Scanner cin = new Scanner(System.in);
		double a,b,c;
		double d;
		double x1,x2;
		a=cin.nextInt();
		b=cin.nextInt();
		c=cin.nextInt();
		d=Math.pow(b, 2)-4*a*c;
		if(d==0){
			x1=-b/(2*a);
			System.out.printf("%.4f\n",x1);
		}
		else if(d>0){
			x1=(-b+Math.sqrt(d))/(2*a);
			x2=(-b-Math.sqrt(d))/(2*a);
			System.out.printf("%.4f %.4f\n",x2,x1);
		}
		else {
			System.out.println("no answer");
		}
	}
}

Python :

from math import sqrt
a,b,c = [float(x) for x in raw_input().split()]
print "%.4f %.4f" %((-b-sqrt(b*b-4*a*c))/(2*a), (-b+sqrt(b*b-4*a*c))/(2*a))

C# :

using System;
namespace C语言
{
    class _2_9
    {
        static void Main()
        {
            string[] s = Console.ReadLine().Split(' ');
            int a = Convert.ToInt32(s[0]), b = Convert.ToInt32(s[1]), c = Convert.ToInt32(s[2]);
            if (b * b < 4 * a * c) Console.WriteLine("no answer");
            else if (b * b == 4 * a * c) Console.WriteLine("{0:f4}", -b / (2.0 * a));
            else {
                double deta = Math.Sqrt(b * b - 4 * a * c);
                Console.WriteLine("{0:F4} {1:F4}", (-b - deta) / (2.0 * a), (-b + deta) / (2.0 * a));
            }
         
            Console.ReadLine();        
        }
     }
}