10.求方程的根

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
    float  a,b,c,s,p,q,x1,x2;
    scanf("%f%f%f",&a,&b,&c);
    s = (-b)/(2*a);
    q = b*b-4*a*c;
    if(q>0)
    {
       p = sqrt(q)/(2*a);
       x1 = s+p;
       x2 = s-p;
       printf("x1 = %7.2f
x2 = %5.2f
",x1,x2);
    }

    else if(q==0)
    {
        x1 = s;
        x2 = s;
        printf("x1 = %7.2f
x2 = %7.2f
",x1,x2);
    }
    else
    {
        printf("方程无实根");
    }

    return 0;
}