C :

#include <stdio.h>
#include <math.h>
void main()
{
	float a,b,c,x1,x2,d;
	scanf("%f%f%f",&a,&b,&c);
	d=b*b-4*a*c;
	if(d<0)
		printf("No solution\n");
	else
		if(d==0)
			printf("x1=x2=%.2f\n",-b/(2*a));
		else
		{
			x1=(-b-sqrt(d))/(2*a);
			x2=(-b+sqrt(d))/(2*a);
			printf("x1=%.2f x2=%.2f\n",x1,x2);
		}		
}

C++ :

#include<iostream>
#include<cmath>
#include<cstdio>
using namespace std;
int main()
{
    float a,b,c,d,x1,x2;
    while (cin>>a>>b>>c)
    {
          d=b*b-4*a*c;
          if (d>=0)
             if (d>0)
             {
                     x1=(-b+sqrt(d))/(2*a);
                     x2=(-b-sqrt(d))/(2*a);
                     if (x2>x1) printf("x1=%.2f x2=%.2f\n",x1,x2);
                     else printf("x1=%.2f x2=%.2f\n",x2,x1);
             }
             else 
             {
                     x1=(-b)/(2*a);
                     printf("x1=x2=%.2f\n",x1);
             }
          else {
               cout<<"No solution"<<endl;
               } 
    }
          return 0;
}