2001*(1/8-1/2009)+8*(1/2001-1/2009)-2009*(1/8+1/2001)+8
=2001/8-2001/2009+8/2001-8/2009-2009/8-2009/2001+8
=(2001/8-2009/8)-(2001/2009+8/2009)+(8/2001-2009/2001)+8
=-1-1-1+8
=5
2001*(1/8-1/2009)+8*(1/2001-1/2009)-2009*(1/8+1/2001)+8
=2001/8-2001/2009+8/2001-8/2009-2009/8-2009/2001+8
=(2001/8-2009/8)-(2001/2009+8/2009)+(8/2001-2009/2001)+8
=-1-1-1+8
=5