35x11/36
=(36-1)x11/36
=36x11/36-1x11/36
=11-11/36
=10又25/36
1997/1998x1999
=1997/1998x(1998+1)
=1997/1998x1998+1997/1998x1
=1997+1997/1998
=1997又1997/1998