Program Mencari Akar Persamaan Kuadrat

program deskrimin ;
uses wincrt;
var a,b,c,d,x1,x2,z1,z2 : real;
begin
writeln ('masukkan nilai a : ');readln (a);
writeln ('masukkan nilai b : ');readln (b);
writeln ('masukkan nilai c : ');readln (c);
d:= b*b-4*a*c;
if a=0 then write ('bukan persamaan kuadrat') else
if d=0 then
begin
x1:=-b/2*a;
writeln ('akar-akarnya sama,yaitu x1=x2',x1:2:2);
end else
if d>0 then
begin
x1:=(-b+sqrt(d))/(2*a) ;
x2:=(-b-sqrt(d))/(2*a);
writeln ('x1',x1:2:2);
writeln ('x2',x2:2:2);
end else
if d<0 then
begin
writeln('akar-akarnya imajiner');
end;
end.