= 2010 * (2000 -1) - 2000 * 2000
= 2010*2000 - 2010 - 2000 * 2000
= (2010 - 2000)*2000 - 2010
= 10*2000 -2010
= 20000 - 2010
= 17990
= 2010 * (2000 -1) - 2000 * 2000
= 2010*2000 - 2010 - 2000 * 2000
= (2010 - 2000)*2000 - 2010
= 10*2000 -2010
= 20000 - 2010
= 17990