Fuente de la vida

        public bool Gauss(double[,] a, double[] r)
        {

            double t, s;

            int i, l, j, k, m, n;



            try
            {

                n = r.Length - 1;

                m = n + 1;

                for (l = 0; l <= n - 1; l++)
                {

                    j = l;

                    for (k = l + 1; k <= n; k++)
                    {

                        if (!(Math.Abs(a[j, l]) >= Math.Abs(a[k, l]))) j = k;

                    }

                    if (!(j == l))
                    {

                        for (i = 0; i <= m; i++)
                        {

                            t = a[l, i];

                            a[l, i] = a[j, i];

                            a[j, i] = t;

                        }

                    }

                    for (j = l + 1; j <= n; j++)
                    {

                        t = (a[j, l] / a[l, l]);

                        for (i = 0; i <= m; i++) a[j, i] -= t * a[l, i];

                    }

                }

                r[n] = a[n, m] / a[n, n];

                for (i = 0; i <= n - 1; i++)
                {

                    j = n - i - 1;

                    s = 0;

                    for (l = 0; l <= i; l++)
                    {

                        k = j + l + 1;

                        s += a[j, k] * r[k];

                    }

                    r[j] = ((a[j, m] - s) / a[j, j]);

                }

                return true;

            }

            catch
            {

                return false;

            }

        }

        public double elixirdelamuerte(int elixir, int veneno, int piscina)
        {
            if (elixir > veneno)
                return -1;
            else
            {
                double[,] a = { { elixir, -1, -piscina}, { veneno, -1, 0 } };
                double[] r = new double[2];
                Gauss(a, r);
                return r[0];
            }
        }