Bài 1:

if (a >0) then write('a la so duong')

else if (a < 0) then write('a la so am')

else write('a la so 0');

Bai 2:

if (a > b) then write('a lon hon b')

else if (a < b) then write('a be hon b')

else write('a bang b');

Bai 3:

if (a mod 2 = 0) then write('a la so chan')

else write('a la so le');

Bai 4:

if (b mod 5 = 0) then write('b chia het cho 5');

bài 1

if a>0 then write(a'la so duong); 

if a <0 then write (a'la so am') else write(a,'la so 0)

bài 2 

if a<b then write(' a lon hon b')

if a=b then write('a bang b')

else write (a nho hon b')

bài 3 

if a mod 2=0 then write (' a la so chan') else write(a la so le)

bài 4

if b mod 5 =0 then write(b'chi hết cho 5')