RUMUS ABC

Mencari akar-akar pers. kuadrat menggunakan rumus ABC

uses wincrt;
var
a,b,c:integer;
D,x1,x2:real;
begin
write('Nilai a = '); readln(a);
write('Nilai b = '); readln(b);
write('Nilai c = ');readln(c);
D:=(sqr b)-(4*a*c);
if D=0 then
begin
x1:=-b/(2*a);
x2:=-b/(2*a);
writeln('x1 = ',x1:8:2);
writeln('x2 = ',x2:8:2);
end
else
if D>0 then
begin
x1:=(-b+sqrt(D))/(2*a);
x2:=(-b-sqrt(D))/(2*a);
writeln('x1 = ',x1:8:2);
writeln('x2 = ',x2:8:2);
end
else
writeln('x1 dan x2 adalah bilangan imginer');
end.