(1001 + 1002 + 1003 + ... + 2012).(360.87 - 720.16 - 360.55)
= (1001 + 1002 + 1003 + ... + 2012).(360.87 - 360.2.16 - 360.55)
= (1001 + 1002 + 1003 + ... + 2012).(360.87 - 360.32 - 360.55)
= (1001 + 1002 + 1003 + ... + 2012).[360.(87-32-55)]
= (1001 + 1002 + 1003 + ... + 2012).(360.0)
= (1001 + 1002 + 1003 + ... + 2012).0
= 0 ( vì 0 nhân bất kì số nào cũng bằng 0)
(1001+1002+1003+.......+2012).(360.87-720.16-360.55)
= (1001+1002+1003+.......+2012).(31320-11520-19800)
= (1001+1002+1003+.......+2012).0
= 0