bai5

#include<iostream.h>

#include<conio.h>

#include<math.h>

void main()

{

int a,b,c,d,e,f;

int m,my,mx;

cout<<"giai he phuong trinh bac nhat 2 an";

cout<<"

ban nhap vao cac he so : a,b,c,d,e,f";

cin>>a,b,c,d,e,f;

m=(a*e)-(d*b);

mx=(c*e)-(f*b);

my=(a*f)-(d*c);

if(m!=0)

{

cout<<"he phuong trinh co nghiem duy nhat";

cout<<"gia tri x= "<<mx/m<<'

';

cout<<"gia tri y= "<<my/m<<'

';

}

else if((m==0&&mx==0)||(m==0&&my==0))

{

cout<<"he phuong trinh vo nghiem";

}

else if(m==0&&mx==0&&my==0)

{

cout<<"he phuong trinh co vo so nghiem";

}

else

{

cout<<"say good bye";

}

getch();

}

bai 6

#include<iostream.h>

#include<conio.h>

void main()

{

      int A[100],n,max,min;

      cout<<"Nhap vao so phan tu can xet"; cin>>n;

      cout<<"

Nhap vao cac gia tri cua phan tu";

      for(int i=0;i<n;i++)

        {

         cout<<"

A["<<i<<"]= ";

         cin>>A[i];

        }

      max=min=A[0];

      for(i=0;i<n;i++)

        {

         if(max<A[i]) max=A[i];

         if(min>A[i]) min=A[i];

        }

      cout<<"

nhap mot so ung voi mot thu tuong tu: ";cin>>at;

switch(at)

{

case 2:cout<<"so nay ung voi thu hai";break;

case 3:cout<<"so nay ung voi thu ba";break;

case 4:cout<<"so nay ung voi thu tu";break;

case 5:cout<<"so nay ung voi thu nam";break;

case 6:cout<<"so nay ung voi thu sau";break;

case 7:cout<<"so nay ung voi thu bay";break;

case 8:cout<<"so nay ung voi chu nhat";break;

default:cout<<"so nay khong ung voi thu nao trong tuan";

}

getch();

}

bai 9

#include<iostream.h>

#include<conio.h>

void main()

{

int m,y;

cout<<"Nhap vao thang m: ";cin>>m;

cout<<"Nhap vao nam y: ";cin>>y;

int m30=(m==4||m==6||m==9||m==11);

int leapyear=(y%400==0||(y%4==0&&y%100!=0));

int numDays=(m==2 ? 28+leapyear : (m30 !=0 ? 30 :31));

cout<<"So ngay cua thang "<<m<<" nam " <<y <<" la "<<numDays;

cout<<endl;

getch();

}