C :

#include <stdio.h>
int main(void)
{
	int x,y;
	scanf ("%d",&x);
	if (x<=5)
	{
		y=x*x+3*x-4;
	}
	else if (x>5)
	{
		y=x*x-5*x+7;
	}
	printf("%d",y);
	return 0;
}

C++ :

#include<iostream>
using namespace std;
int main()
{
	int x,y;
	cin>>x;
	if (x<=5) y=x*x+3*x-4;
	else y=x*x-5*x+7;
	cout<<y<<endl;
	return 0;
}