Finding Delta and Roots

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

float delt(float a,float b,float c){
    float sonuc;
    sonuc= b*b-4*a*c;
    return sonuc;
}

float solve(float a,float b,float c,float *root1,float *root2){
    float delta,sonuc;

    if(a==0){
        return -1;
    }

    delta=delt(a,b,c);

    if(sonuc==0){
        *root1=(-1*b/2*a);
        return 1;
    }

    if(sonuc<0){
        return 0;
    }

    *root1=(-1*b+sqrt(delt(a,b,c)))/2*a;
    *root2=(-1*b-sqrt(delt(a,b,c)))/2*a;
    return 2;
}
int main(){
    int solved;
    float a,b,c;
    float r1,r2;
    scanf("%f%f%f",&a,&b,&c);
    solved = solve(a,b,c,&r1,&r2);
    if(solved == -1) {
        printf("not quadratic\n");
    }
    if(solved == 1){
        printf("r1=r2: %f",r1);
    }
    if(solved == 2){
        printf("r1: %f r2: %f",r1,r2);
    }
    system("pause");
    return 0;
}