Solving a quadratic equation in C

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

int main(){
float a,b,c,delta,r1,r2,x;
printf("\n a: ", a);
scanf("%f", & a);
printf("\n b: ", b);
scanf("%f", & b);
printf("\n c: ", c);
scanf("%f", & c);
delta =b*b-(4*a*c);
if(a==0){
if(b!=0){
x=-c/b;
printf("\nA simple root: %f\n",x);
}
else if(c==0) printf("\nInfinity of roots\n");
else printf("\nNo Solutions\n");
}
else{
if(delta> 0){
r1 =(b-sqrt(delta))/(2*a);
r2 =(-b-sqrt(delta))/(2*a);
printf("\nThere are two solutions: %f %f\n",-r1,r2);
}
else{
if(delta==0){
r1 =(-b)/(2*a);
printf("\nThere is a solution: %f\n",r1);
}
else printf("\n Delta is negative so no real roots\n");
}
}
return 0;
}