Bài 1:

#include <iostream>
using namespace std;
long long a;
int main() {
    cin >> a;
    if(a % 2 == 0)
        for(int x = 0; x <= a; x+=2)
            cout << x << " ";
    else
        for(int x = 1; x <= a; x+=2)
            cout << x << " ";
    return 0;
}

Bài 2:

#include <iostream>
using namespace std;
double a, b;
int main() {
    cin >> a >> b;
    if(a > b) cout << a;
    else cout << b;
    return 0;
}

Bài 3

#include <iostream>
using namespace std;
long long int a, b, c, d;
int main() {
    cin >> a >> b >> c >> d;
    cout << "So lon nhat la: ";
    if(a > b && a > c && a > d) cout << a;
        else if(b > c && b > d) cout << b;
            else if(c > d) cout << c;
                else cout << d;
    cout << "\nSo be nhat la: ";
    if(a < b && a < c && a < d) cout << a;
        else if(b < c && b < d) cout << b;
            else if(c < d) cout << c;
                else cout << d;
    return 0;
}

Bài 4

#include <iostream>
using namespace std;
long long int a, b;
int main() {
    cin >> a >> b;
    if(a == 0 && b > 0) cout << "Vo so nghiem";
        else if(a == 0 && b < 0) cout << "Vo nghiem";
    cout << "x";
    if(a > 0) cout << " > " << -b/a;
    else cout << " < " << -b/a;
    return 0;
}

Bài 5:

#include <bits/stdc++.h>
using namespace std;
long long int a, b, c, delta;
int main() {
    cin >> a >> b >> c;
    delta = b*b - 4*a*c;
    if(delta < 0) cout << "Phuong trinh vo nghiem";
    else if(delta == 0) cout << "Phuong trinh co nghiem kep x1 = x2 = " << -b/a;
    else cout << "x1 = " << (-b+sqrt(delta))/(2*a) << "\n" << "x2 = " << (-b-sqrt(delta))/(2*a);
    return 0;
}

$#khanhtaon$

\begin{array}{c} \color{#db1616}{\texttt{#Khoadang09}} \end{array}
`@`$\texttt{C++: }$

*Bài 1 :

#include <iostream>
#define int long long
#define buff ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
using namespace std;
signed main(){
    buff;
    int n; cin >> n;
    if (n%2==0) for (int i=0;i<=n;i+=2) cout << i << " ";
    else for (int i=1;i<=n;i+=2) cout << i << " ";
    return 0;
}

*Bài 2 :

#include <iostream>
#define int long long
#define max(a,b) (a>b?a:b)
#define buff ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
using namespace std;
signed main(){
    buff;
    int a, b; cin >> a >> b;
    cout << max(a,b);
    return 0;
}

*Bài 3 :

#include <iostream>
#define int long long
#define max(a,b) (a>b?a:b)
#define min(a,b) (a>b?b:a)
#define eol '\n'
#define buff ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
using namespace std;
signed main(){
    buff;
    double a, b, c, d; 
    cin >> a >> b >> c >> d;
    cout << max(a,max(b,max(c,d))) << eol;
    cout << min(a,min(b,min(c,d)));
    return 0;
}

*Bài 4 :

#include <iostream>
#include <iomanip>
#define int long long
#define buff ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
using namespace std;
signed main(){
    buff;
    double a, b; cin >> a >> b;
    if (a==0){
        if (b==0) cout << "Vo nghiem";
        else 
            if (b>0) cout << "Vo so nghiem";
                else cout << "Vo nghiem"; //(b<=0)
    }
    else if (a>0)
        cout << fixed << setprecision(2) << "x > " << -b/a;
    else 
        cout << fixed << setprecision(2) << "x < " << b/a;
    return 0;
}

*Bài 5 :

#include <iostream>
#include <iomanip>
#include <cmath>
#define int long long
#define eol '\n'
#define buff ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
using namespace std;
signed main(){
    buff;
    double a, b, c; cin >> a >> b >> c;
    if (a<0) cout << "Vo nghiem";
        else if (a==0) 
            cout << fixed << setprecision(2) << "Nghiem duy nhat x1 = x2 = " << -b / (2*a);
    else {
        double delta = b * b - 4 * a * c;
        cout << fixed << setprecision(2) << "X1 = " << (-b+sqrt(delta))/ (2*a) << eol ;
        cout << fixed << setprecision(2) << "X2 = " << (-b-sqrt(delta))/ (2*a);
    }
    return 0;
}