/*giai he ptrinh bac nhat*/

#include<stdio.h>

#include<string.h>

#include<conio.h>

int main()

{

  float x,y,a2,b2,c2,a1,b1,c1;

  float d,d1,d2;

  printf("nhap he so a1,b1,c1:");

  scanf("%f%f%f",&a1,&b1,&c1);

  printf("nhap he so a2,b2,c2:");

  scanf("%f%f%f",&a2,&b2,&c2);

  d=a1*b2-a2*b1;

  d1=c1*b2-c2*b1;

  d2=a1*c2-a2*c1;

  if(d!=0)/*dx=d1*/

      {

          x=d1/d;

          y=d2/d;

          printf("he ptrinh co 1 nghiem x=%.2f, y=%.2f",x,y);

      }

   else

      {

          if((d1==0)&&(d2==0))

              printf("he ptrinh co vo so nghiem");

          else

              printf("he ptrinh vo nghiem");

      }

   getch();

   return 0;

}