[Ghost]

Yurij
Вот тебе исходник для вычисления определителя:

uses
  crt;

const
  n = 2;

type
  vector = array [1..32] of real;
  matrix = array [1..32] of vector;

var
  a: matrix;
  b, c: vector;
  i, j: byte;
  p: boolean;
  res: real;

procedure Determinant (x: matrix; size: byte; var Result: real);
var
  y: vector;
  i, j, k: byte;
  p: real;
begin
  Result := 0;
  for i := 1 to size do y[i] := 1;
  for i := 1 to pred (n) do begin
    if x[i, i] = 0 then begin
      k := succ (i);
      while (k <= size) and (x[k, i] = 0) do inc (k);
      if x[k, i] = 0 then exit;
      p := y[i]; y[i] := y[k]; y[k] := p; y[i] := -y[i];
      for j := i to size do begin
        p := x[i, j]; x[i, j] := x[k, j]; x[k, j] := p;
      end;
    end;
    p := x[i, i]; y[i] := y[i] * p;
    for j := i to size do x[i, j] := x[i, j] / p;
    for k := succ (i) to size do begin
      p := x[k, i];
      for j := i to size do x[k, j] := x[k, j] - p * x[i, j];
    end;
  end;
  Result := x[size, size];
  for i := 1 to pred (size) do Result := Result * y[i];
end;

procedure Gauss (x: matrix; y: vector; size: byte; var Result: vector; var isResult: boolean);
var
  i, j, k: byte;
  p: real;
begin
  isResult := False;
  for i := 1 to size do Result[i] := 0;
  for i := 1 to pred (n) do begin
    if x[i, i] = 0 then begin
      k := succ (i);
      while (k <= size) and (x[k, i] = 0) do inc (k);
      if x[k, i] <> 0 then begin
        p := y[i]; y[i] := y[k]; y[k] := p;
        for j := i to size do begin
          p := x[i, j]; x[i, j] := x[k, j]; x[k, j] := p;
        end;
      end;
    end;
    if x[i, i] <> 0 then begin
      p := x[i, i]; y[i] := y[i] / p;
      for j := i to size do x[i, j] := x[i, j] / p;
      for k := succ (i) to size do begin
        p := x[k, i]; y[k] := y[k] - p * y[i];
        for j := i to size do x[k, j] := x[k, j] - p * x[i, j];
      end;
    end;
  end;
  if (x[size, size] = 0) and (y[size] <> 0) then exit;
  if x[size, size] = 0 then Result[size] := 0
                       else Result[size] := y[size] / x[size, size];
  for i := pred (size) downto 1 do begin
    Result[i] := y[i];
    for j := succ (i) to size do
      Result[i] := Result[i] - x[i, j] * Result[j];
  end;
  isResult := True;
end;

begin
  clrscr;
  randomize;
  writeln ('start matrix:');
  for i := 1 to n do begin
    for j := 1 to n do begin
      a[i, j] := random(10);
      write (a[i, j]:8:2);
    end;
    b[i] := random(10);
    writeln (' | ', b[i]:8:2);
  end;
  Determinant (a, n, res);
  writeln ('determinant = ', res:8:2);
  Gauss (a, b, n, c, p);
  if not p then writeln ('net reshenija') else begin
    for i := 1 to n do writeln ('x[', i:2, '] = ', c[i]:8:2);
  end;
  readkey;
end.

Чуть попозжа напишу решение СЛУ методом Гаусса.

З.Ы. Добавил в код метод Гаусса. Кажись все работает...