Bagaiman mencari Determinan Matrik???

program determinan;
uses wincrt;
var A : array[1..2,1..2] of integer;
j,k,D : integer;
begin
For j:=1 to 2 do
begin
write('Entrikan baris ',j,' matriks A : ');
readln(A[j,1] , A[j,2]);
end;
For j:=1 to 2 do
begin
For k:=1 to 2 do write(A[j,k] : 5);
writeln;
end;
writeln;writeln;writeln;
D := A[1,1]*A[2,2] - A[1,2]*A[2,1];
writeln('Det(A) = ',D);
end.