#include<map>
#include<set>
#include<queue>
#include<stack>
#include<cmath>
#include<cstdio>
#include<vector>
#include<string>
#include<cstring>
#include<ctype.h>
#include<iostream>
#include<algorithm>
using namespace std;
#define INF (1 << 30)
#define LINF (1LL << 60)
#define PI acos(-1.0)
#define mem(a, b) memset(a, b, sizeof(a))
#define rep(i, a, n) for (int i = a; i < n; i++)
#define per(i, a, n) for (int i = n - 1; i >= a; i--)
#define eps 1e-8
#define debug puts("===============")
#define pb push_back
#define mkp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
#define POSIN(x,y) (0 <= (x) && (x) < r && 0 <= (y) && (y) < c)
typedef long long ll;
typedef unsigned long long ULL;
int main()
{
  int test;
  ll a[100005];
  scanf("%d", &test);
  rep(iii, 0, test) {
    int n;
    scanf("%d", &n);
    rep(i, 0, n){
      scanf("%lld", &a[i]);
    }
    sort(a, a+n);
    ll sum = 0;
    ll ans = 0;
    for (int i = 0; i < n; ++i) {
      sum += a[i] - a[0];
    }
    for (int i = 0; i < n; ++i) {
      if (i!=0) sum -= (a[i]-a[i-1]) * (n-i);
      ans += sum;
    }
    printf("%lld\n", ans);
  }
}