ktltbai01.cpp

#include <stdio.h>

int main()
{
    // Khai bao bien
    float a1,b1,c1, a2,b2,c2 ,d,dx,dy;
    
    // Nhap lieu
    printf("a1 = ");
    scanf("%f",&a1);
    printf("b1 = ");
    scanf("%f",&b1);
    printf("c1 = ");
    scanf("%f",&c1);
    
    printf("a2 = ");
    scanf("%f",&a2);
    printf("b2 = ");
    scanf("%f",&b2);
    printf("c2 = ");
    scanf("%f",&c2);
    
    
    // Tinh dinh thuc 
    d  = a1*b2 - a2*b1;
    dx = c1*b2 - c2*b1;
    dy = a1*c2 - a2*c1; 
    
    // Tim nghiem
    if(d != 0){
        printf("He phuong trinh co nghiem duy nhat\n");
        printf("x = %f \n", dx/d);
        printf("y = %f \n", dy/d);
    }else{
        if(dx != 0 || dy != 0){
           printf("He phuong trinh vo nghiem \n"); 
        }else{
            printf("He phuong trinh vo so nghiem \n");
        }
    }
    return 0;
}