#include <iostream> 2 #include <stdio.h> 3 using namespace std; 4 5 void PTB1 (double a , double b) { 6 if (a == 0) { 7 if (b == 0) 8 cout << "VSN"; 9 else cout << "VN"; 10 } 11 else 12 printf("%.2f",-b/a); 13 } 14 int main() { 15 double a , b; 16 cin >> a >> b; 17 PTB1(a , b); 18 return 0;

- Chương trình 1 :

#include <iostream>

using namespace std;

int main()

{

    float a, b;

    cout << "Nhap he so a, b = "; 

    cin >> a >> b;

    if ((a == 0) && (b == 0)) cout << "PT vo so ngiem";

    if ((a == 0) && (b != 0)) cout << "PT vo nghiem";

    if (a != 0) cout << "x = " << -b / a;

    return 0;

}

- Chương trình 2 :

#include <iostream>

using namespace std;

int main()

{

    float a, b, c, d, s = 0;

    cout << "Nhap 4 so a, b, c, d = ";

    cin >> a >> b >> c >> d;

    if (a < 0) s += a;

    if (b < 0) s += b;

    if (c < 0) s += c;

    if (d < 0) s += d;

    cout << "Tong so am = " << s;

    return 0;

}