UVA 12502 Three Families

#include <bits/stdc++.h>
#include <math.h>
#include<string>
#define pi acos(-1.0)
#define ll long long int

using namespace std;

int main() {
    ll t;
    cin >> t;
    while(t--) {
        ll a, b, c;
        cin >> a >> b >> c;
        cout << c*(2*a-b)/(a+b) << "\n";
    }
    return 0;
}