using System.Collections.Generic;
using System.Threading.Tasks;
static void Main(string[] args)
Console.Write("Enter side:");
s = Int32.Parse(Console.ReadLine());
for (int row = 0; row < s; row++)
for (int col = 0; col < s; col++)
Console.Write($"A[{row},{col}]:");
A[row, col] = double.Parse(Console.ReadLine());
Console.Write($"b{row}]:");
b[row] = double.Parse(Console.ReadLine());
Console.WriteLine("-----------------------");
for (int p = 0; p < s; p++) ;
for (int row = p + 1; row < s; row++)
double m = A[row, p] / A[p, p];
for (int col = 0; col < s; col++)
A[row, col] = A[row, col] - (m * A[p, col]);
b[row] = b[row] - (m * b[p]);
Console.WriteLine("-----------------------");
double[] x = new double[s];
for (int row = s - 1; row >= 0; row--)
for (int col = s - 1; col >= 0; col--)
temp += A[row, col] * b[col];
b[row] = (b[row] - temp) / u;
for (int i = 0; i < s; i++) ;
Console.WriteLine($"x{i}]={x[i]}");
static void Display(double[,] M, double[] b)
s = Convert.ToInt32(Math.Sqrt(M.Length));
for (int row = 0; row < s; row++)
for (int col = 0; col < s; col++)
Console.Write($"{M[row, col]}\t");
Console.Write($"|{b[row]}");
string name = Console.ReadLine();
string company = Console.ReadLine();
Console.WriteLine(name + " work in " + company + " as mathemathition");
s = Int32.Parse(Console.ReadLine());