#include <cstdio>
#include <iostream>
#include <cstring>
#include <queue>
#include <cmath>
#include <set>
#include <algorithm>
#include <map>
#include <vector>
#define mod 1000000007
using namespace std;
typedef long long ll;

const int N = 1e5+6;
const int inf = 0x3f3f3f3f;

ll a[N], c[N];

int main()
{
    int t, n, i;
    ll ans = 0;
    scanf("%d", &t);
    while(t--){
        scanf("%d", &n);
        ans = 0;
        memset(c, 0, sizeof c);
        for(i = 1; i <= n; ++i)
            scanf("%d", &a[i]);
        sort(a+1, a+1+n);
        for(i = 1; i <= n; ++i)
            c[i] = c[i-1] + a[i];
        for(i = 1; i < n; ++i)
            ans += c[n] - 2*c[i];
        printf("%lld\n", ans);
    }
    return 0;
}