Câu 1 :

uses crt;

var a : array[1..3] of real;

tb : real; i, j : byte;

begin

clrscr;

write('nhap diem van, toan, tieng anh : ');

readln(a[1], a[2], a[3]);

tb := (a[1] + a[2] + a[3]) / 3;

writeln('Diem trung binh ba mon : ', tb:2:2);

if tb >= 8 then writeln('Xep loai gioi');

if (tb < 8) and (tb >= 6.5) then writeln('Xep loai kha');

if (tb < 6.5) and (tb >= 5) then writeln('Xep loai trung binh');

if (tb < 5) and (tb >= 3.5) then writeln('Xep loai yeu');

if tb < 3.5 then writeln('Xep loai kem');

for j := 3 downto 2 do

for i := 1 to j - 1 do 

if a[i] < a[i + 1] then 

begin

a[i] := a[i] + a[i + 1];

a[i + 1] := a[i] - a[i + 1];

a[i] := a[i] - a[i + 1];

end;

write('Sap xep diem : ');

for i := 1 to 3 do write(a[i]:3:1,'  ');

readln

end.

Câu 2 :

uses crt;

var a, b, c, dt : real;

begin

clrscr;

write('nhap he so a, b, c :');

readln(a, b, c);

dt := b * b - 4 * a * c;

if a <> 0 then

begin

if dt >0 then

begin

writeln('nghiem x1 =', ((- b + sqrt(dt))/(2 * a)):2:2);

writeln('nghiem x2 =', ((- b - sqrt(dt))/(2 * a)):2:2);

end

else if dt = 0 then writeln('x = ', (-b / (2 * a)):2:2)

else writeln(' Phương trinh vo nghiem');

end;

readln;

end.