Bài tập giải hệ PT bậc nhất !

//Giai he PT bac nhat

//Khai bao thu vien
#include
#include
void main()
{
//khai bao bien
float a1,b1,c1,a2,b2,c2,d,dx,dy,x,y;
char ans;
//vong lap do ... while de thuc hien cong viec lap lai bai giai he PT
do
{
clrscr();
printf("Chuong trinh giai he PT bac nhat");
//nhap du lieu
printf("\n Nhap a1 = ");scanf("%f",&a1);
printf(" Nhap b1 = ");scanf("%f",&b1);
printf(" Nhap c1 = ");scanf("%f",&c1);
printf(" Nhap a2 = ");scanf("%f",&a2);
printf(" Nhap b2 = ");scanf("%f",&b2);
printf(" Nhap c2 = ");scanf("%f",&c2);
//xu ly du lieu
d=a1*b2 - a2*b1;
dx=b1*c2 - b2*c1;
dy=a1*c2 - a2*c1;
if (d==0)
{
if (dx==0 && dy==0)
printf("\n He PT co vo so nghiem! ");
else
printf("\n He PT vo nghiem! ");
}
else
{
x=dx/d;
y=dy/d;
printf("\n He PT co 2 nghiem la: ");
printf("\n\t x = %f",x);
printf("\n\t y = %f",y);
}
printf("\n Ban co muon tiep tuc CT (y/n)? ");
ans=getch();
}while (ans =='Y' || ans =='y');
}