Const
   N = 4;
Var
   A:array[1..N,1..N] of real;
   B,X,AX:array[1..N] of real;
   i,j:integer;
   S:real;
Begin
Randomize;
Write('B(',N,'):');
For i:= 1 to N do
    Begin
    B[i]:=random(721)-360;
    Write(' ',B[i]:4)
    End;
WriteLn;
Write('X(',N,'):');
For i:= 1 to N do
    Begin
    X[i]:=random(721)-360;
    Write(' ',X[i]:4)
    End;
WriteLn;
WriteLn('A(',N,',',N,'):');
For i:= 1 to N do
    Begin
    Write('     ');
    For j:= 1 to N do
        Begin
        A[i,j]:=random(721)-360;
        Write(' ',A[i,j]:4)
        End;
    WriteLn;
    End;
WriteLn;
Write('AX:');
For i:= 1 to N do
    Begin
    AX[i]:=0;
    For j:= 1 to N do
        Begin
        AX[i]:=AX[i]+A[i,j]*X[j];
        End;
    Write(' ',AX[i])
    End;
WriteLn;
Write('AX+B:');
For i:= 1 to N do
    Begin
    X[i]:=AX[i]+B[i];
    Write(' ',X[i])
    End;
WriteLn;
Write('|Ax+b| = ');
S:=0;
For i:= 1 to N do
    Begin
    S:=S+X[i]*X[i];
    End;
WriteLn(Sqrt(S))
End.


Пример:
B(4):  -51  179  276 -273
X(4): -272 -261  -57  304
A(4,4):
      -169  -94  245 -346
      -351 -176  280    1
      -193 -330  219  -54
       338  -57  -44 -328

AX: -48647 125752 109727 -174263
AX+B: -48698 125931 110003 -174536
|Ax+b| = 246563.556248688