Question

19991999x 1998-19981998x 1999

Answer 1

1999.10001.1998-1998.10001.1999
=1999.1998(10001-10001)
=1998.1999.0=0
________________________
li-ke cho mk nhé bn
 

Answer 2

1999.10001.1998-1998.10001.1999

=1999.1998(10001-10001)

=1998.1999.0 = 0