[Kailon]

Предлагаю свой вариант решения:

Код:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Math, StdCtrls, Grids;

type
  TForm1 = class(TForm)
    SG1: TStringGrid;
    Button1: TButton;
    SG2: TStringGrid;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

const
  aMin = 0; aMax = 9;

var
  Form1: TForm1;
  aRnd: array [aMin..aMax, aMin..aMax] of SmallInt;

implementation

{$R *.dfm}

procedure FillArray;
var
  I, J: SmallInt;
begin
  for I := aMin to aMax do
  for J := aMin to aMax do
    aRnd[I, J] := RandomRange(-25, 25);
end;

procedure ChangeSign(Col, Row: Byte);
var
  I: SmallInt;
begin
  for I := aMin to aMax do
  if (I <> Col) and (I <> Row) then
  begin
    aRnd[I, Row] := aRnd[I, Row] * (-1);
    aRnd[Col, I] := aRnd[Col, I] * (-1);
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  C, R: SmallInt;
begin
  FillArray;
  for R := aMin to aMax do
  for C := aMin to aMax do
    SG1.Cells[R, C] := IntToStr(aRnd[R, C]);
  ChangeSign(4, 4);
  for R := aMin to aMax do
  for C := aMin to aMax do
    SG2.Cells[R, C] := IntToStr(aRnd[R, C]);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Randomize;
end;

end.