Membuat Program Pascal - Akar Kuadrat

Program mencari_akar_kuadrat;
uses crt;
var x1,x2,x3,D:real;
a, b, c:integer;
begin
clrscr;
writeln('mencari akar pers a*x*x+b*x+c');
write('Koef a =');readln(a);
write('Koef b =');readln(b);
write('koef c =');readln(c);
if A = 0 then
begin
x1:=-c/b;
write('harga x=',x1:1:3);
end
else
begin
D:=b*b-4*a*c;
if D>0 then
begin
x1:=(-b-sqrt(D))/2.0*a;
x2:=(-b+sqrt(D))/2.0*a;
writeln('nilai Diskriminan =',D:1:3);
writeln('nilai x1=',x1:1:3);
writeln('nilai x2=',x2:1:3);
readln;
end
else
if D=0 then
begin
x1:=-B/2.0*a;
writeln('nilai Diskriminan = 0');
writeln('nilai akar-akar sama');
readln;
end
else
begin
x1:=-b/2.0*a;
x3:=-sqrt(abs(D))/2.0*a;
writeln('nilai diskriminan =',D:1:3);
writeln('dua akar imajiner');
writeln('nilai akar x1=',x1:3:1,'+',abs(x3):3:1);
writeln('nilai akar x2=',x2:3:1,'-',abs(x3):3:1);
readln;
end
end
end.