D := (b * b) - (4 * a * c);
if (D < 0 ) then
writeln('Rovnica nema riesenie')
else if (D = 0) then
begin
x := (-1 * b) / (2 * a);
writeln('Koren rovnice je: ', x:5:5);
end;
else
begin
x := ((-1 * b) + sqrt(D)) / (2 * a);
y := ((-1 * b) - sqrt(D)) / (2 * a);
writeln('Korene rovnice su:',x:5:5,', ',y:5:5);
end;