const n=5;
type ar=array[1..n,1..n] of integer;
procedure p1(var m:ar);
var i,j:integer;
begin
for i:=1 to n do
  for j:=1 to n do m[i,j]:=random(10)-5;
end;

procedure p2(h:char;var m:ar);
var i,j:integer;
begin
writeln('--',h,'--');
for i:=1 to n do
 begin
  for j:=1 to n do write(m[i,j]:4);
  writeln;
 end; 
end;
 
procedure p3(var m1,m2,m3:ar);
var i,j,k,s:integer;
begin
for i:=1 to n do 
 for j:=1 to n do
 begin
 s:=0;
 For k := 1 to n do s:=s+m1[i,k]*m2[k,j];
 m3[i,j]:=s;
 end;
end;

var a,b,c : ar; 
begin
Randomize;
p1(a); p2('A',a);
p1(b); p2('B',b);
p3(a,b,c); p2('C',c);
end.

Пример:
--A--
   3  -4  -5  -4  -2
  -1  -4   2  -2   0
   2  -5  -5  -2  -5
  -4   1  -5   0   4
   1   0   2   1   0
--B--
   4   3  -2   0  -5
  -5  -3   2   2   2
  -5  -4  -3   2   4
  -1   2  -3  -4   3
   4   3  -1   4   4
--C--
  53  27  15 -10 -63
   8  -3  -6   4  -1
  40  22  12 -32 -66
  20  17  21   8  18
  -7  -3 -11   0   6