C :

#include<stdio.h>
#include<math.h>
int main()
{
	double a,b,c;
	void root(double a,double b,double c);
	scanf("%lf%lf%lf",&a,&b,&c);
	if(a!=0.0) root(a,b,c);
	getchar();
	getchar();
	return 0;
}
void root(double a,double b,double c)
{
	double x,root1,root2;
	if (b*b-4*a*c>=0)
	{
		x=sqrt(b*b-4*a*c);
		root1=(-b+x)/(2*a);
		root2=(-b-x)/(2*a);
		printf("r1=%7.2f\n",root1);
		printf("r2=%7.2f\n",root2);
	}
	else printf("No real roots!\n");
}

C++ :

#include <cstdio>
#include <cmath>
int main (void)
{
	double a,b,c,r1,r2;
	scanf("%lf%lf%lf",&a,&b,&c);
	if((b*b-4*a*c)<0){
		printf("No real roots!\n");
	}else {
		r1=(-b+sqrt(b*b-4*a*c))/(2*a);
		r2=(-b-sqrt(b*b-4*a*c))/(2*a);
		printf("r1=%7.2f\nr2=%7.2f\n",r1,r2);
	}
	return 0;
}