substitution and determinant

#include<stdio.h>
int main()
// substitution and determinant
{

    double a1,a2,b1,b2,c1,c2,D,X,Y;
    printf("a1= ");
    scanf("%lf",&a1);
    printf("a2= ");
    scanf("%lf",&a2);
    printf("b1= ");
    scanf("%lf",&b1);
    printf("b2= ");
    scanf("%lf",&b2);
    printf("c1= ");
    scanf("%lf",&c1);
    printf("c2= ");
    scanf("%lf",&c2);
    D=a1*b2-a2*b1;
   if((int)D==0){
    printf("value of x  and y can not be determined.\n");
   }
   else{
   X=(b2*c1-b1*c2)/D;
   Y=(a2*c1-a1*c2)/D;
   printf("x=%0.2lf,y=%0.2lf\n",X,Y);}
     return 0;



}