#include <bits/stdc++.h>
using namespace std;
template <class T>
inline bool chmax(T &a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
inline bool chmin(T &a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
const long long INF = 1e18;
using lll = pair<pair<long long, long long>, long long>;
long long N;
vector<long long> a;
vector<lll> ans;
bool ALLSAME(vector<long long> v) {
  for (int i = 1; i <= N; i++) {
    if (v[i] != v[1]) return false;
  }
  return true;
}
void f(long long i, long long j, long long x) {
  if (x == 0) return;
  assert(1 <= i and i <= N);
  assert(1 <= j and j <= N);
  assert(x >= 0);
  a[i] -= x * i;
  a[j] += x * i;
  assert(a[i] >= 0);
  ans.push_back({{i, j}, x});
  return;
}
void print() {
  for (int i = 1; i <= N; i++) cerr << a[i] << " ";
  cerr << "\n";
}
void g() {
  if (ALLSAME(a)) return;
  long long sum = 0;
  for (auto tmp : a) sum += tmp;
  if (sum % N != 0) return;
  long long target = sum / N;
  long long from = -1;
  long long val = 0;
  for (int i = 2; i <= N; i++) {
    if (chmax(val, a[i] / i * i)) {
      from = i;
    }
  }
  if (from != -1) {
    f(from, 1, a[from] / from);
  }
  vector<pair<long long, long long> > v;
  for (long long i = 2; i <= N; i++) {
    long long need = 100000 * i - a[i];
    need %= i;
    v.push_back({need, i});
  }
  sort(v.begin(), v.end());
  for (auto tmp : v) {
    long long idx = tmp.second;
    long long need = tmp.first;
    if (need <= a[1]) {
      f(1, idx, need);
      f(idx, 1, a[idx] / idx);
    }
  }
  for (int i = 2; i <= N; i++) {
    if (a[i] < target) {
      long long need = target - a[i];
      if (a[1] >= need) {
        f(1, i, need);
      }
    }
  }
}
void solve() {
  cin >> N;
  a.resize(N + 1);
  ans.clear();
  for (int i = 1; i <= N; i++) {
    cin >> a[i];
  }
  g();
  if (!ALLSAME(a)) {
    cout << -1 << "\n";
    return;
  }
  cout << ans.size() << "\n";
  for (auto tmp : ans) {
    cout << tmp.first.first << " " << tmp.first.second << " " << tmp.second
         << "\n";
  }
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long T;
  cin >> T;
  while (T--) solve();
  return 0;
}
